[ratbusters]

Hi there and welcome to the forum.
She looks like she could well be. Has she been in with a male in the last couple or so weeks? Is she still sharing a cage with other rats?
You could set up a birthing cage for her just in case she is pregnant. Once they start to show, they have the babies within a week.
Here is a link how to do the cage:

 

[ratbusters]

Well all the best and keep us posted!
She and the babies will have have a safe home now.
If you haven't experienced a rat giving birth before, you might find these links helpful. One is what to expect for a normal labour/delivery and one is about labour emergencies.
Most rats seem to do just fine having their babies but its good to know when to be concerned.
I am not a breeder or anything but we had accidental babies about a year and a half ago.

Labor and Birth – Rat Guide

ratguide.com

Labor Emergencies – Rat Guide

ratguide.com

 

[ratbusters]

Awww congratulations on the babies' safe arrival.
They look comfortable in their nest.
It looks like they have some really good milk bands - those white stripes across their tummies which are actually tummies full of milk!