Valentine

[Card]

Well, again it's a matter for conjugation (sorta). By the way, I'd recommend looking up a website, I just did a quick search and found a decent looking one, just in case you're curious about future verbs. People often forget about it, but conjugation is very important and we use it every time we write or talk. I had a friend (smart guy, in most cases) who told me English didn't have conjugated verbs. He was wrong, oddly enough. He also thought Allah was only the God of Islam though, so maybe I give him too much credit.


Anyways, to answer the actual question being discussed:
"Her" is an object, and "she" is a subject. Basically, if she is the one doing it, she is the subject. If she is the one having something done to her, she is the object. You can have multiple of each, of course, so don't just look for one. Typically, in a well-built sentence, the subject will be on the left of the verb, and object on the right. You will occasionally find them switched, especially when creative license is taken. But rarely are they on the same side of the verb, if ever.

In the first line, you are asserting your sentiment for her.
(You might be tempted to think only one is the object, but it's important to separate them. It's your sentiment, not hers. So you're asserting it, for her.)

Second time, she is stirring up your emotions.

Oh, and in the unmentioned third time, she controls your emotions.