The Pitchei Teshuva YD 195:19 cites the Chamudei Daniel as saying that a niddah shouldn't go to a cemetery to daven. The Mishna Brurah 88:7 writes that a niddah shouldn't go to a cemetery. Shiurei Shevet Halevi 195 writes that a niddah shouldn't go to the cemetery because of a concern of mystical reason of tumah. However, it is permitted for her to go and stand 4 amot from the grave.
Does this all apply to a single girl?