I told her she might avoid a yeast infection by taking Lactinex (lactobacillus), a probiotic that replenishes the good bacteria that antibiotics kill. She reported later that the Lactinex worked--and that it wasn't worth $100 to get a yeast infecton.
A few weeks ago, I had stomach aches and motion sickness while I was taking cleocin (another antibiotic). Normally, I can spin and spin without getting dizzy, let alone seasick. But I was suddenly unable to even read on the bus. Taking probiotics (Udo's Choice Super 5 Lozenge Probiotic) made me feel better. Super 5 contains lactobacillis acidophilus, bifidobacterium bificum, streptococcus thermophillus, l. bulgaricus and l. salivarius. Some of these are in various brands of yogurt, but you'd have to eat a lot of yogurt to get as much flora, and it's not a good idea to eat dairy if you're already nauseated.
You can find probiotics at drug stores and health food stores. They have to be refrigerated, so you may have to ask the pharmacist for a bottle if there is no self-serve section.