Lots of time - most bones take 6-8 weeks to set, which takes you to the start of June and 1st summer session. But with a foot that takes a bit more stress than say and arm or hand, it may well be wise to keep stress off the foot for longer. She can still do some cardio and a lot of weight room as the only thing she can't stress is the foot itself so she shouldn't be losing much fitness and she should have plenty of time post recovery before the season.