If she is a virgin, it will probably take about a year. If she is not and she likes sex, then two months is probably the longest you'll have to wait. Either way, don't pressure her for sex.
Just go for it, if you both want it, there's no reason why you shouldn't, unless she doesn't want to, don't pressure her into anything, if you do, you are likely to push her further away, be accepting of her and make sure she knows that you like her for her, not her body or the sex. if you do this then the sex between you will be great.
Good luck and have fun