Skin around the eyes is probably the most delicate skin of the body. If your child has been rubbing their eyes, the area will easily turn red.
Rubbing — in and of itself — isn’t really cause for concern, unless what’s making your baby rub is more serious. (Do keep in mind that fingers + eyes = recipe for infections.)
It's hard to tell from the pic but it looks like little one has a fever?
If so, send her to the PD asap.
Red under the eye may be a result of eye infections called cellulitis, which when occurring around the eyes are called periorbital cellulitis.
Have it treated quick k.