I’ve been looking for the same one for myself (autistic adult) for a few years, it seems like it’s impossible to track down. I recommend setting up two alerts for eBay, one specific and one broad. I found one of the prints I was looking for but the seller didn’t list the specific print or year. “Vintage gymboree blanket 90’s” is a good starting point. Moon and star is also a good key phrase.
I’ve seen some people recommend Facebook in the past but I can’t speak to that since I’m not on there
Good luck! I hope your daughter will be able to have the same special blanket as us <3