Substitute for eggs in Macarons (No Legumes)

My absolute favorite things to bake are French macarons. I make them for family gatherings, potlucks, or just to give to my public library. A huge issue, however, is that often times I just make them at home for my family, but my mom is allergic to eggs, so she can never eat them. For a while I've wanted to find an alternative to egg whites for the meringue. I found out about chickpea water (Aquafaba) and other legumes, and started to plan getting those and making meringue using Aquafaba. But then I ran into another issue. My mom told me how she's allergic to not only chickpeas, but ALL legumes. Now I am completely lost on how to make macarons for her.

I thought about whipping up heavy whipping cream into hard peaks (assuming it could function the same as meringue). You're whipping air into something and I thought that's the most important part of macarons. Does anyone know if this works or does anyone think I should try using heavy whipping cream?

Finally, is there anything other than legumes that I could use in place of egg whites in meringue? A reply would be greatly appreciated.