My proper name is obviously Robert but to my family and former work colleagues I've always been known as Bob ( or Bobby to my uncle/aunts/grandparents when I was very young) and to my girlfriend and friends I've made via the internet,I'm known as Rob.
I did ask Kate (my girlfriend.....who incidentally is known as Kate,Katie,Catherine,Cath and Cathy......depending on who's talking to her

) if she wanted to call me Bob to tie in with my family......or Rob, but she chose the latter,not particularly liking the former.
It can get complicated.
But back to Stina / Kristina........the name is getting quite close to Chris / Chrissie,the girl in 'A Walk In The Park'.
