There are two genres of the 'boys kissing' you refer to, shounen-ai which is innocent romance, and yaoi which is more explicit. Depending on the sites she's using these are tagged, you do have to dig harder for more explicit stuff so you can keep her away from it with a certain amount of ease.
For your own peace of mind, if you want to put down a restriction, ask her to stick to a single site to watch anime. Crunchyroll is a good resource, most of the up-to-date stuff is there and it's age-controlled.
www.crunchyroll.com/videos/anime
As for genres for her to keep away from, that's a bit more difficult. I would suggest sticking to shounen and shoujo (boy's and girl's series respectively) but a few of them can cross the line into other territories. Attack on Titan is huge at the moment, everyone's watching it, as is Kill la Kill, but it's up to your own discretion and how mature you feel your daughter is to decide whether she can watch them or not.
All in all, though, I wouldn't worry too much. I got into this stuff at a similar age and it's a very innocent way to explore your feelings on certain things without engaging in any real-world way that could lead to trouble. She will likely want to watch what her friends are watching, so if you get her to give you the names I can advise you on an individual basis (I do it all the time over here anyway).
Also, why not try sitting down and watching with her once in a while? I'd reccommend the new Sailormoon Crystal, it could be a nice way to bond with her and see things the way she does for a bit.