Could it be possible to download something like that and print it out on fabric? I've never done anything like that before, but do remember someone talking about it. I'm not too sure how it would wash, but there must be a lot of folks on this forum who could give you more accurate suggestions.
And how nice that you have a sweet SIL like that. Makes you feel more like your daughter got lucky in the marriage sweepstakes, as mine did.
Whoops..didn't read the letter above before running off at the mouth (or fingers..just washed my hands and can't do a thing with my fingers.)