I am so sorry for your loss. No one ever truly gets over losing one's mother. You have my empathy.
If you can, get in touch with someone who does textile restoration and get their evaluation. If you ruin one of these tops, they aren't replaceable. If you can't, get a good book on quilt top restoration, or Heirloom quilt restoration. There are a couple of really good ones out there. Remember that the fabrics used by your Mother are not the modern fabrics we have today. The older fabrics didn't go though the fancy processes that helps retain colors so they bleed more easily. I know. I lost a quilt top my Great Grandmother made when I soaked it in COLD water with a special quilt soap (Restore) and the greens ran dreadfully. The green patches were faded, and every other patch was stained green! Plus the old thread holding the patches together just disintegrated in the water in places, and I was removing the quilt top in pieces. I was devastated! This was after I was told by the Textile restoration person this would be a safe process for this particular quilt top. When I told the Textile Restoration Person about what happened, she was upset and said she wished she'd told me to used Retayne first. What is that? Retayne is a color fixative for commercially dyed cotton, linen and rayon fabrics that bleed. Use in the washing machine or treat by hand washing with hot water. Always test fabric before washing it for the first time. Only one application is necessary. That would have fixed the colors, prevented the bleeding, and anything else that happened could have been repaired. I've got some now, and am using it when I pre-wash my fabrics.
So my advice is yes, go ahead and do it, but educate yourself first, in all aspects of restoration, and know what you're dealing with. Losing a quilt top like that is heartbreaking. I am only fortunate I had two left.
Kindest Wishes,