Is it normal for my cousin and i to finger each other?

When I was 12 years old I went and stayed with my cousin during the school holidays,she lived a long way from us, so I didn't see her very often,she was 14 years old, they had a spare room and I slept in that room,she was good fun to play with,on the second day that I was there it was raining a little,and we were playing in the shed at the bottom of the back yard, we were playing near an old lounge suit that was in there when I fell back on to the lounge suit, as I tried to get up, my cousin jumped on top of me, we were both laughing,I then felt her hand going up my leg, my skirt was up my legs and I saw and felt her fingers going up under the leg of my knickers,I went to push her hand away but she stopped laughing and said to me to come on and let her do it to me,before i could do anything I felt her hand moving inside my knickers and her fingers going down between my legs,and she fingered me,after a little while she looked up at me and said that she had her finger all the way up inside me and that it felt nice,I said to her to stop it that someone could come into the shed and see us, and that we were cousins,but she just said that no one would come down to the shed as it was raining, and she kept moving her finger around inside me before she took her finger out, she then looked at her finger and smiled and said that it felt nice, she said that we could sleep together, but I didn't, she fingered me again before I came home, and she asked if I wanted to do it to her that it feels nice, but I didn't,
was it wrong what she did, or for me to let her do it to me because we were cousins?