A woman who is required to take birth control pills (medically, and after speaking to a Rov), and she must take them at the same time daily- if the time she takes them can sometimes be on Friday night, after it gets dark but before Kiddush, can she still take it then?
1. Medication may be taken before Kiddush, even if one needs to take some water with it. However, if one needs to take food with it, this may not done before Kiddush.
2. Even so, unless there is a compelling reason otherwise, this question can easily be avoided by making Kiddush first.
3. To the best of my knowledge, birth control pills do not have to be taken at the same exact time. Usually this is recommended only in order that one get into a routine and not forget to take them. Even with the progesterone only pill, the min pill, which must be taken on a consistent basis at the same time, There is leeway of up to three hours.
ראה שו״ת מנח״י ח, יח. שש״כ נב, ג. חוט שני פה, ב בסופו.