What remedies to stop 4 month old puppy eating her own poop ?

Picking it up as soon as it is produced would be the easiest way :-)

I do that but she tries to beat me to it !!

Distract her then :-)  Be ready with something super tasty or a toy she really loves, then as soon as she's finished, start waving it around in front of her and acting silly to get her distracted and forgetting about it.  Do that every time and it should become habit that she walks away from it, before it becomes habit that she eats it.

Most importantly - don't tell her off or rush to grab it!  You'll make her think that there's something very special about it, and all she'll do is eat it faster!

ETA what do you feed her?  That can make a difference too, and when was she last wormed?

Rather than rushing up to it work on the recall command as well.

I've tried pretty much all the so-called remedies for this and the ONLY thing that works is to be there and pick it up.  I've had some who have gone right ahead when I'd said 'don't you DARE' and gone for the pooper scooper only to find it's gone in the meantime!!   You might look at the diet because for me, it happens more often when feeding a low-grade diet with tons of fillers.   This sort of food tends to pass through without being fully digested, making what comes out the other end, still appealing.   As my first experience of this was with our third hound, our foundation bitch when she was pregnant for the first time, I also tend to favour the theory that something is missing in the diet so the dog goes at what comes through again.  

Add -    You are right about shouting making them gobble it up faster ...... sometimes with our numbers, I'd be at the kitchen sink and not out there when it was produced, resulting in me yelling (my fish-wife action) and running out by which time they'd gobbled and run!!