[cypher]

There have been other members with hamsters of a similar age go through this type of surgery & recover well, a lot depends on the individual hamster but there's a good chance Rosie will do fine.
There aren't really any special foods that you need to give but you would most likely need to give some meds after the operation & that's easiest done with a tiny amount of soft food, either hamster safe baby food or porridge, this usually works well with most hams.
If she's on antibiotics afterwards then you might want to give a probiotic like Pro C (available from P@H or other pet shops) for a while too, don't put it on water though just sprinkle it on food a few hours apart from meds.
If Rosie still enjoys her normal food then just keep up with that, a good variety of veg if she's used to those will give extra vitamins & other nutrients which may help her recovery too.
Good luck with her, hope all goes well.