
I can only tell you what happened when I had the same situation (my younger bitch was also 2 and 1/2). Mum was fine with her daughter right up to going into labour, obviously they were separated whilst she had her babies, and she stayed exclusively with them for 3 days. After this, mum asked to come and see her daughter and started to spend small amounts of time with her. After a week we thought that mum may let her daughter see the pups, so we took her in on her lead and mum was quite happy with her daughter at a distance - she made it clear at first just how close she could come. After a very short time when curiosity was satisfied we let her in without a lead, and she would lie and watch the puppies, not attempting to get too close. Obviously her mother never considered her the threat she seemed to think our male dog was - she would not let him any where near her babies until they were about 4 weeks old, and even then would guard them. By the time the pups were 3 weeks, mum was happy to let the other bitch wash them and play with them but still supervised to make sure her daughter didnt get too heavy handed in play, and by the time they went to their new homes, they had two mothers to say goodbye to! Obviously it may vary with your two, but if you follow mothers lead and make sure the daughter has lots of human company, I'm sure they will be fine! :D