Some children can be scared of something and have a hard time putting into words.
If it's a major problem, you might see if she would be willing to consider desensitization therapy. You could start by asking if she would be willing to see a picture of your dogs. Start there. Once she is okay with that, ask if she would be willing to be in the room with the dogs when they are on a lead and under your control. When she's comfortable with being around them, maybe she would like to try having them closer to her, and eventually giving them a treat.
I do have to ask, though, is there even the remote possibility that the dogs have nipped or scratched her? Even small dogs can potentially do a fair amount of damage, and size isn't always consistent with temperament. (I'm not saying yours are, but as an example, some small dogs are downright nasty, while some large dogs can be big, goofy, friendly things that would probably walk up to trouble and lick it all over.) Are the dogs trained? If they're not, they could still be overwhelming for her. If the dogs aren't trained, putting them in an obedience class may be beneficial.