Hi there,
It looks like a RES, but I'm also not quite sure ( I'll look into it )
yes it is too early to determine the sex of the turtle. Cute name by the way
Does your grandma know the species? Maybe you could ask her.
Or maybe you could find out where she got the turtle?
Sorry for my lack of knowledge about this xD
If you have any more questions, don't hesitate to ask!
EDIT:
I looked into it more, and compared both the RES and CST. can you send me another picture of its ears so I can confirm the species?? Thanks!
Fish keeper & Turtle know it all... Ish