Grats on your new family member! lady sniffles is adorable.
I have ratties too. They do best in pairs. You can keep boy/girls together as long as you neuter or spay one.
Nice you got her out of the aquarium. The most common ailment among rats are uri’s. Aquariums are terrible for that. Dusty substrates is also not great with them.
Diet wise, rats are much more like us than rabbits and can eat a variety of foods, even ones that are not good for other pets-such as avocado and chocolate. Most people put them on a good block food and then give them veggies, fruits and grains daily. You can do your own mix, which I do, but that is a bit more complex since they need a good variety of foods to meet nutritional requirements. Easy things to do though-feed them their block food. (oxbow is one of the most commonly used ones) They can eat many of the fresh greens your bunnies eat, though not in such quantity. They can also eat a lot of your foods. As an example if I make pasta, rice or a grain, I will take a portion of cooked pasta out that does not have salty sauces or such on it for the rats. I will give them some of our human salad without the dressing or onions. When I make stews, which I do often in the winter I don’t add salts to it and leave that on the table for the humans to add and that way I can make a little portion up for the rats. They enjoy oatmeal in the morning with me topped with a little soymilk. I don’t add sugar to theirs. If we have chicken, I’ll give them the bones to chew on.
http://www.isamurats.co.uk/feeding-and-nutrition.html
You will find a ton of conflicting information online about rat care. I gave you someone’s website above there that I trust, and it gives a lot of basic information. The conflict I think arises since there are so many raising them as food for other pets, use in labs and then as pets themselves.
Being rats have been used in labs for a very long time you can look up information on almost any subject on rats and find studies done as well. If you are obsessive with your pet care, as I am their is a lot of information on rats.
Lifespans are relatively short, unfortunetly, being about 18 months to 3 years being the average.
They are very smart, many equate them to small dogs and can be taught in a lot of the same tricks as dogs and as easily.
lastly watch out for a pregnancy since she was in with a boy. We have 3 girls (We’ve always kept them in 2-3) and one was pregnant with 12. So we have 2 huge cages now one with 7 girls and the boy cage with 8. That was a little over a year ago and definately more than we ever intended. We’ve had rats for a little over 30 years and I’ve never had more than 3 so it’s been…well interesting.