Gentle Giants gave you good advice. It is really hard to tell if a rabbit is pregnant. (They hide it real well!) You will just have to be ready, just in case.
Are you keeping her indoors or out? What breed is she (or how much does she weigh?) Do you know how old she is? Is she is a cage big enough to accommodate a nest box? If you can give her a nest box, it needs to be located in a corner that she doesn't usually pee or poop. I prefer to put a 2" layer of absorbent wood shavings on the bottom, then pack the box with straw. (I prefer using straw because the momma is less likely to eat the straw, than if you used hay.) She will dig a hole in the middle and (hopefully) before she delivers, she will pull fur off her own belly and sides to line the nest.
After the babies are born, you CAN touch them. You will need to make sure all the babies are alive and well.. Remove anything that didn't make it, as well as any leftover placenta's. (No, the momma may not do this.) Make sure the nest is clean and dry. Your smell on the babies will NOT keep her away from them...
You can check on them everyday to make sure they are getting fed and are growing. They are born with their eyes closed and the eyes will open around 10 days after birth. They will start coming out of the nest box around 2 weeks of age. When they start coming out, I like to give them pellets to start eating, mixed with rolled oats (plain cooking Quaker oats cereal). I don't feed them greens or fruits until after they are weaned and over 3 months of age.
Please keep us informed! We love to hear about babies! (And see pictures!) If you have any questons, don't hesitate to ask.... And thank you for being willing to take on a "possibly pregnant" girl. Hugs to you for being so kind.