Or instead, maybe you could simply talk to her.
This spell sounds a lot more like a spell to control than anything and the fact that you don't seem to know what to do makes me nervous about your magickal knowledge.
Before casting you really need to know what you are doing and the dangers of it, you can't rely on others to do it all for you.
Magick should not be used to solve everything, try discussing it with her first before you try to force her to forgive you, if you need a spell for her to forgive you, then maybe she shouldn't.
I am not being hateful in anyway, it is simply the way the post was written and the lack of information we have on you.