I think that the separation is much harder for mum to cope with than for bubs. Especially if she is at home with her dad, who I assume she is already comfotable being around. It is probably a good idea to start leaving her a bit more so she (and you) can get used to the idea though.
When I went back to work part time, my boys went into daycare. For a couple of weeks before I started back I took them to the centre for a half day and built it up so it wasn't such a shock for them when it was full days.
Unfortunately it was still really hard leaving them, and 9 months on, sometimes they just want to be with mummy and it is still really hard to say good bye. You just have to get tougher, and make the most of the time you do get to spend with her.