Reminding her of her mother is not a problem. She really likes to talk and laugh about stuff her mom used to do, or things she used to say. She doesn't get upset the second she hears the word mom. I bring up things she's told me about her mom all the time. We have plenty of inside jokes that stem from something her mom said, and they always make her smile. So something literally involving the memory of her mom wouldn't be as bad as it seems like it might be. Believe me, I thought of this too.
That being said, if I did get her something like that, I wouldn't give it to her randomly. I'd probably keep it around my apartment and when one of those nights occur where she's sleeping over and we get talking about her mom and family a lot, I'd give it to her. I'm not going to pick her up from work someday and hand her a picture of her mom, that would be weird. I know I said I wanted to give it to her in two days when I pick her up from the airport, but I don't have to do it then. She'd probably be too tired from the flight anyway. I'm thinking the time away did her good and hopefully she comes back in better spirits.
I am however going to cook her favorite food and borrow her dog from her sister's place and have him greet her at the door when she walks into my apartment. But I cook for her all the time, so I kinda want to do something else.
I know it's hard for you guys to know since you don't know her at all and only a few people in the world know her as well as I do, but she is highly unlikely to get offended by a gift I gave her unless it was intentionally mean spirited (which I would never do). I could make the most bonehead move in the world or give her a very unintentionally offensive gift and she wouldn't get upset because she knows that I would've meant well.
I'll keep thinking for a week or two and see how she's doing. Better than rushing something.
Suggestions still are needed though.
Thanks for the help so far.