Looking on the internet deeply has found these results:

suitable for her is the most popular phrase on the web.

suitable to her 13,620,000 results on the web	suitable for her 149,700,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	I think there are other schools more suitable for her. I don't know that he's suitable for her. You're very suitable for keeping her child! So I need to think about a suitable husband for her. We grew up together, but my station always prevented me from being a suitable choice for Her Serene Highness, at least I have always worried about her marriage, as it is difficult to seek a suitable gentleman for her There isn't anyone around here remotely suitable for her.

suitable to her

13,620,000 results on the web

suitable for her

149,700,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

I think there are other schools more suitable for her.
I don't know that he's suitable for her.
You're very suitable for keeping her child!
So I need to think about a suitable husband for her.
We grew up together, but my station always prevented me from being a suitable choice for Her Serene Highness, at least
I have always worried about her marriage, as it is difficult to seek a suitable gentleman for her
There isn't anyone around here remotely suitable for her.