Apollo is leash reactive towards tiny/toy/teacup dogs (and small puppies). We've been working on it, and he's been doing great, I'm so proud of him. But, I have noticed that when I put him in a "sit" when a tiny dog is passing by if he backs up on my feet or is touching my legs or really any part of me his growl is a lot louder and deeper. If I don't let him touch me at all, just look at me, it's like the dog isn't even there, no growling at all.
I think Apollo touches me to "claim" me. But, I have no idea if your dog is doing that because she loves you or wants a pat or is claiming you or something else.