Firstly I'd be teaching her a very informal 'stay', using small actions on your part that mimic real life. So start with moving a step away in different directions, much like a normal stay, but then add in other things such as heading for the door (and building up to going through it), playing with the TV, looking at the paper, sorting cushions on the sofa, etc etc - basically anything and everything that you might do in real life. The only rule is that if she stays put, she gets a treat. It also tends to work better if she is in a relaxed down position first - so laid down with hips to one side (easy to lure) - as dogs are less likely to get up from this position and in and of itself, it is more relaxing to be in. When you reward her, use quiet praise and pop the treat between her front feet. That helps keep her down there. I also don't use a clicker for this, as it tends to get them more excited!
Once you've got her to the point that you can wander around, go in other rooms, to the loo etc without her following, you can start to leave her for gradually longer periods., always with quiet praise and the odd treat when you return.
At the point, try and leave her fairly often - IME the number one cause of separation anxiety is when puppies are not left alone at all because people don't want them to get separation anxiety! And it does sound like you're heading down that road at present. By 11 weeks she should be able to cope with being left for a short time indoors, if not you leaving the house altogether for short periods.
I would also reconsider doggy daycare: it certainly has value, it has its place if it's well run, but from what you've described, you are setting her up to need constant input and attention and no off switch. If you are at home and asleep, provided she's had some stimulation and has got something to chew on or otherwise occupy her, and loo breaks of course, she should settle along with you even at that age. Daycare is not always a great environment for dogs too, to be frank - have you been along to see how the other dogs are? Too many just throw a load of dogs in together and it becomes an excellent training ground for bullies and OTT players.
By the by, the above exercise will also help to teach her that off switch that as a springer, she will need if she's to be a well-rounded, contended adult. I'm all for giving dogs plenty of stimulation and many do not get enough, but it is also possible to provide too much and end up with a wired dog that cannot settle until bedtime.