Do all girls like to stimulate themselves?

When i met my girlfriend first time, she was so innocent and looks like she never ever did or have thinking about the sex or things related to it ,( i had same feelings to other girls also), but after 2 months i was so open to her n i got to know she is a kind of turned on girl who also do mastrubate everyday i was shocked that i was thinking she is innocent but she is really different, so my question is that do all girls are like that who seems innocent but there is somthing naughty in them which they keeps with them only. Whether mastrubation is usual thing for girls, they are more intrested in doing these things? I am worried about my girlfriend that is not doing right please make me understand that girls are really innocent but they need mastrubation nothing wrong in that? thanks in advance