I find slip-ons hard to fit with my narrow heels -- they don't stay on and are uncomfortable. But I love the look. I have had one pair that worked, but I fear for me at least it would involve so much trying to get that one pair.
It's so great you are going to see your family!
A bunch of silver options from Finds, but some are older. I have the Ecco lace ups. I wear an insole with them because sneakers are too flat for me otherwise. They do accommodate a Superfeet insole (i.e. they are roomy in my regular size).
JAileen has the Fitflops. Unfortunately, they don't fit me, or I'd have got them, because the sandals are great for my plantar fasciitis.