I didn't know she has those periods to contend with. But it's good that she has learned to spot when they are coming/occur and reach out to her support network.
No need to tell us anything, it's totally up to Sarah. There are people on here with more complex mental health conditions and this place is very non judgemental about such things so whilst she only needs say what she feels comfortable with I hope she doesn't worry how she will be perceived.
I'm glad she has her friends around her. At hard times what we often need is some normality and just a laugh a cry or to sit watching the TV having a chat to pull you through.