Female mother can't get "infected". They can be pollinated if they're flowering. The pollen has to land on an actual pistil for a seed to be produced. If they are mothers in veg they won't be pollinated except potentially on a few preflowers which won't ruin the plants. If you don't want the male for pollen to make more seeds then get rid of it and clean the pollen from your grow area.
And yes some strains can develop male flowers in veg.