Hi, Gina! I don't know how many days you let go in between your emails. Unfortunately, though, some are not as good as others about letting you know if the item has been sold. My advice would be: if this person is taking a long time to get back with you, look elsewhere. In this way, you will not be kept waiting while the item you want is being sold by someone else. If you have to wait a long time for a response, if something happens with the sale, it will be even more difficult to reach her, possibly.
Generally, one to two days is fair, in my opinion.