Welcome Joy!! You sound like such a wonderful, responsible pet family. :-) Your snake is just beautiful!!!! You'll love this forum, and you'll learn a lot. :-)

One thing you might consider is the pre-frozen feeder mice... having had rescued pet mice and rats myself, that was a hard concept for me to deal with but I also wanted my snakes to have the best nutrition for them (it's not their fault they're snakes, you know?) So I did a lot of research and found a company that talked about the health, comfort and welfare of their feeder mice, and also described the euthanasia method. It's not so hard to feed these frozen mice when you know they were bred exactly for this reason and treated humanely.

But I think if your comfort level is the fish, your snake will still be fine. Do you have an established fish tank you can keep feeder fish in? Then you could buy more at a time...

Keep us posted! :-)