Both of mine were about 11 mths old when they started to take a milk bottle sometimes, although both were breastfed past that, and the sleepover was at my mums where they were very familiar with from being there for day sleeps etc. when i was working. DD had her first sleepover at MILs a few months ago but they are an hour and a half away. As for sleep-overs - I don't even want to think about it yet! Especially if it is a friend at school and you aren't that familiar with the family/friends who go there. Going to be tricky I think!