Thanks for writing in.
There are two issues here:
1. Mucus and blood: Mucus and blood may appear after masturbation
in females, especially if they have used a significantly larger and/ or sharper object into the vagina. This needs to be clarifed with your friend.
2. Losing virginity: Virginity is a social term used to denote females who have not had penetrative sex. Breaking of hymen
can take place even during activities like horse riding or playing athletic sports. Hymen can get broken during rough masturbation also. This does not mean losing virginity.
Hope this helps.