Hello, I really hope that I can get some advice regarding my situation.
I have 2 female dogs, Sheba is a boarder collie/husky mix and is 9 years old. Sheba is the alpha dog in our home. Our other dog, Crispy, is 4 years old and is 1/4 boxer, 1/4 German shepherd, and the other half is unknown.
A little history of these dogs, Sheba is very kind and gentle, very obedient, we really have no complaints of Sheba, she is the kind of dog everyone wants their dog to be, never ever have had an issue with her. Sheba is the alpha dog, in that she has to eat first and sets the tone, but that is really the only alpha traits she shows.
Crispy came into our home when Sheba was about 5, Crispy was a few months old. Crispy is a little bit hyper, likes to go outside often, but all in all fairly lazy and laid back. These two dogs have been best friends! Crispy even has a little bit of separation anxiety from Sheba when we have to take one of the dogs to the vet.
About a 2 weeks ago, Crispy suddenly attacked Sheba, biting her neck and shaking her neck, not letting go. My boyfriend and i tried to pull Crispy away, but she would not let go. finally Crispy let go, but after i was bitten myself! I am certain this was triggered due to a laser pointer that Crispy likes to play with, but Sheba does not like for Crispy to play with this toy; Sheba will growl and bark at Crispy if she is playing with this toy. We threw the laser pointer away, punished Crispy for this behavior, and thought that would be the end of it.
Well, just yesterday it happened again, same thing, Crispy grabbed hold of Shebas neck, shaking her neck and biting her neck. I was by myself this time, but managed to pull Crispy off of Sheba and put Crispy outside and punished her. This time, however, I think what triggered this behavior was me trying to get Sheba to take her medicine (Crispy took her medicine first with no problem), but Sheba was being very stubborn and would not take her medicine. I was trying to give Sheba her medicine, and Crispy was watching me (didn't even think anything of it). Sheba got away from me and there Crispy goes, she attacked her.
I am so concerned about this new behavior. Never ever has anything like this happened and now it has happened twice in 3 weeks! When Crispy attacks Sheba, Sheba does nothing and just lets Crispy attack, fortunately Sheba has not been seriously injured, but I am afraid something worse might happen.
Any feedback would be much appreciated! At the moment, I am putting Crispy on "bootcamp" terms (I.e. making her sit before going outside, not giving her unnecessary pets on the head, kisses, or hugs unless she deserves it). Am I doing the right thing or is there more to it than that? I have not been keeping Sheba to "bootcamp" rules, but I now think I need to do this with both dogs so Crispy doesn't do this again due to jealousy.

Please help!!! Thank you!

You need to get a behaviourist out to observe these two dogs in their home, and work out what is going on and advise you on how to work on the issues.  Some things concern me - for one thing, punishing a dog when there is tension to the point of aggression is totally counter-productive, all it does is add stress to an already stressful situation which will make the aggressor more likely to snap (imagine how short a fuse people have if they're under a lot of stress compared to when they're relaxed).  "Bootcamp" may also make things worse if the cause of this is down to stress as suddenly changing how you interact with Crispy will stress him out, especially restricting affection like that with him and not Sheba.

With the sudden onset I would also advise a full vet check for BOTH dogs, including full bloods and thyroid panels (full, not just T4 or T4/TSH as these are not reliable by themselves).  You say that Sheba is on medicine and was being "stubborn" and not taking it - this suggests she was not happy about it, especially if she was trying to get away from you and Crispy could have been picking up on that and getting stressed by it, resulting in aggression.  What is wrong with Sheba that she needs medicine?  Perhaps this needs a review and medication tweaking.

Has anything changed for either dog lately, such as exercise, walking locations, a bad experience, food, routine?  Anything at all :-)

A behaviourist is a must I think though, in order to see the body language between the two dogs and towards/related to you and your OH.  Whatever you do, avoid someone who talks about pack leaders, being 'top dog', showing them who's boss, etc etc - it's all a fallacy and will not help.  Likewise avoid somebody who uses punishment.

First, am I right in thinking that both bitches are spayed?

Yes, they are both spayed.

Thank you for the feedback!
Sheba is actually taking thyroid medicine, this is a new thing we have started, probably about a month now that Sheba has been taking it (her thyroid is under active). We take her back to the vet in a few months to see if it has been regulated with the medicine.
I have been observing Shebas behavior towards Crispy, and Sheba acts very cautious, almost scared when Crispy comes around her.

Also, there has not been any changes, except for the addition of the thyroid medicine for Sheba.

I am certain this was triggered due to a laser pointer that Crispy likes to play with

What?!!!!!!!

I'd defernatly second a full medical check, it could be she has a health problem causing the attacks.  did you notice how crispy was acting right befor the attacks?

A friend had 2 GSD, farther and son so all ways been together, the son was about 4-5. One day he suddenly attacked his farther, seemed out of the blue as both dogs ware lieing down one minit fighting the next. It kept happening randomly and then they noticed right befor the attacks the son would suddenly stare at the farther and freeze right befor he attacked. They took him the the vets and eventually it turned out he had a brain tumor.

I haven't really noticed the look Crispy gives before she attacks, but I am definitely going to take her to the vet to have her checked out. Hoping this is a medical condition that can be treated. I appreciate all the feedback from everyone! Thank you all so much!

assume this is those little red pointer lights that some cat's like to chase, like pouncing on a torch beam.

Maybe the thyroid problems in the older dog is the trigger for the younger one to react??

I second the advice, full medical checkups for both girls...Sheba too- you need to quickly exclude any medical reason for this sudden change in behaviour.

Get a good behaviourist in asap- don't try to solve this on the forum. Google APBC or UKRCB for someone in your area.