ok, I don't know if I can help and I am worried you think I can
Ds did not sleep through until he was 3 and we put him in his own room
In fact he still doesn't sleep through every night but whatever...
Erm so I really do know how you feel. First of all before I tried anything else I would start going to bed when she does. Yes I know it is horrific but you must have some sleep. Just do this for a few nights until you feel sentient again.
After that, have you tried any form of night weaning at all or have you always just done the she squeaks, you feed her thing? What happens if you try to just cuddle and pat her? What happens if she goes to sleep somewhere other than your bed (mattress on the floor?) does she still wake up at the same time / as frequently? We found a bit of distance helped the wakings become less frequent, over a very long period.
Have you read the No Cry Sleep Solution? Any good? There is one for toddlers which is the one you need. She starts off assuming you are bf and co-sleeping and takes it from there, it is totally child-centred.
If I said "I have a crystal ball and there is nothing you can do to solve this, she will go on waking until she is 3 whatever you do, so just concentrate on meeting her needs" how would you feel? What would you do?
How much understanding does she have? Can you explain things to her? If you took the tack of comforting her but not feeding her, and she cried in your arms at times during the night, would it bugger things up with waking up ds, dp's work etc?
Sorry for all questions but it is very hard indeed isn't it? I do want to give sensible advice and hope I can do...