Tashy embryos are donated on and is something many do consider and use. I know a lady that recently gave birth to a bub that was a result of a single embryo donation from a couple that decided not to use their frozen embryo left over from a successful egg donor cycle. The donating couple and their egg donor were all involved. A beautiful outcome - 2 children to 2 different families as a result of one egg donation and then one embryo donation. Embryo donation like egg donation can be known (eg through a site like AED) or unknown (eg through a clinic).
Sending you lots of hugs and so pleased you are looking at all the possibilities xx