We are remodeling my daughter's bedroom.

Do you mean that the bed has legs (as opposed to being on a solid platform) and that just the four legs have made sunken impressions into the wood subfloor? In that case, subfloor can be either plywood or a composite material, both of which are soft. You can try placing a damp washcloth over the areas and steam ironing gently over them. This will swell the wood back up and sometimes you can't even tell they were ever depressed. Just don't get the iron too hot. Good luck.

Did the sub floor sunk around the whole bed or just at one spot under a leg?

This article should be helpful for you! https://www.oldhouseonline.com/articles/how-to-fix-sagging-floors

Allen, if the legs are on rollers, purchase those flat, hard rubber molded square or round brown rubber thingees at Walmart that you set the feet on to prevent them leaving marks on the floor. Can't think of the name of them right now, but they come in packs and there is a circle in the center for the leg to set down in. The idea I gave you previously should work and these rubber things should prevent more damage. You could also put a sheet of vinyl (Home Depot/Lowes sells remnant pieces rolled up - 6x9's) under the bed, and that would help.