1) A small amount of toe overlap is unlikely to cause problems;
2) The posers here who say she should suck it up and deal with it or quite riding fixed are self-important punks. Ignore them.
3) My fixie is a converted 1985 Fuji Espree with almost no overlap. It is possible to find frames that have less, and frames that have much more. The challenge is weighing every trade-off you make. Finding a frame that has exactly the feature-set you want may be challenging....