DD is 6m old
she took her 1st bottle at 9 days, and by 5 weeks old took 1 bottle of expressed milk a day from Daddy.
About 6 / 7 weeks ago her sleep was terrible and 3 expression sessions a day was not enough to make 1 bottle per day, so I went back to BFing her at bed time.
In this 6 / 7 weeks she has started weaning and learnt to drink water from a sippy cup.
She has had 4 bottles of very watery juice in an attempt to get her to sleep all night without milk (it worked, she now sleeps)... her 1st bottle of slightly less watery juice she drank a few oz nicely.... the last couple where it was a splash if juice in 8oz of water she didnt really like so didnt drink, and more messed with the teat, not impressed!
I went out yesturday and left Daddy with a bottle of expressed milk, and she didnt / wouldnt drink it... she just chewed the teat and tried to use it as a sippy cup 
I was only out for the morning but as soon as she saw me she wanted booby milk and drank lots.
Is it possible she has forgotten how to use a bottle?
Can i get her to re-learn?
I can barely express 2oz a day at the moment (and i use it all, + dwindling freezer supplies for her breakfast and baby rice that she has for pudding at tea time)
Issue is in a couple of months I am leaving her all day (and evening etc) with grandma and she will need to drink her milk including bed time milk. (2 child free weddings)
I dont want her to not settle, or at 8m old to go 24 hours without milk.
Any tips? can i get her back to a bottle.
she drinks from a sippy cup, but only small sips... i cant imagine she would drink 8oz (or even 2oz) from her sippy cup