Is my cousin a lesbian?

I'm traveling to Taiwan with my cousin and a female friend of hers, they're both in their late 20s. I'm a 14 year old girl. I'm wondering if my cousin and her friend are lesbians ( I would support them if they are), because during our stay at a relative's house last night, we were in the same room with a bunk bed, I was on the top bunk and they were sharing the bottom bunk. I was woken up by a noise in the middle of the night so I quietly took a look below. They had their bodies completely covered up, with only their hands hanging out. They were holding both hands, and it seemed like a test of strength of some kind. They stayed like that for at least an hour, holding both hands, pushing each other. I was a little scared because I thought they were fighting. What were they doing?