Worried I won’t be able to do DLI for my Mom if needed

My mom is +85 days post SCT. She hasn’t yet had a bone marrow biopsy done but is having one this week. I was her donor in May but my husband and I are trying for a baby, and I’m worried if she needs a DLI that I might be pregnant and won’t be able to donate any more cells. Has anyone ever done a DLI with a different donor? We were told my brother could have been her original donor previously, but that I had slightly better markers. I’m assuming it’s preferred to use the original donor? I didn’t even know about DLIs until seeing a post today. We planned to start trying for a baby in January but put it off so I could be my moms donor in the Spring. Currently she is full donor chimerism.