Should i get a new cage mate for my rat and if so how long should i wait?

I had2 hooded female rats and unfortunately I had to put down one yesterday because an infection sprang upon her from post op surgery for mammory tumors. They've been together since I got them two years ago as babies and I was wondering if I should get my other one a cagemate because my parents work a lot and won't have time to constantly hold her and give her affection. I'm also leaving again for college and as much as I want to take her with me I can't but I don't want her to be lonley. I'm considering adopting an older female as a cage mate. If I do get another roughly the same age i want to do it soon so my parents are comfortable as well as my rat with the new pet to the household before I leave.