I'll second that mind the fingers comment. In all my years of handling rats this is the only time I have ever been bitten.

If you need to put your hand in her space, be sure to do so on her terms.

Give her around 24-48 hours to adjust. You will want to check to see if they have milk bands within the first 24 hours just to be sure all is going well. Since tomorrow is Christmas & all the stores where you would find rat supplies are closed you wouldn't be able to get any supplies if needed. Maybe you should get a can of formula tonight "just in case". You can use the puppy (esbilac) or kitten (KMR) formula & a small eye dropper. Both have been well received from babies I have hand fed. Don't open it until you need it & if you do open it, freeze what you don't immediately use into small ice cubes & store them in a zipper sealed bag. Mix the full strength formula with equal parts water when thawing. Even if you don't need it & Mom does well on her own, you can offer it to her while she is nursing.

Consider having formula & an eye dropper on hand "just in case" as a staple when you are breeding or have a pregnant rat. (especially if you want the babies to grow up beyond pinky aged feeders)