The pursuit of sperm donor siblings

My partner gave birth to our kids using an anonymous sperm donor (who was my first choice for donor). Our kids know this. For over 4 years, we have been in contact with another family who used the same donor. We meet regularly as schedules permit. Our kids recognize the other family as their half-siblings and like / love those half-siblings. Through that family, we know of, but have only met once, another family.

Recently, another family via the same donor contacted that other family and we reached out to this new family, which is in contact with 2 other families. Confusing, I know. I obfuscate deliberately. Suffice it to say, our kids know some half-siblings via their donor father and are about to know some more.

If I were one of my kids, I would want to know every thing I could about my biological relatives, especially since the donor is anonymous and currently, unknowable. However, I would also be worried about the feelings of my non-bio mom. I'd want to make sure she did not feel betrayed or threatened. Hence, I, the curious non-bio mom, have pursued this matter.

I think having a network of biological relatives may be even more important since the parents of these donor sperm-produced kids are older. And the relatives are older. The siblings may need each other as they get older. Even more as they age and lose immediate family. They may need each other for health issues: organ donation, diseases, etc. They will need to know who not to date. Mostly, they will need each other for support and understanding. These kids did not chose to be born to single moms and lesbian couples (and maybe straight infertile couples) and they did not chose their circumstances. I want my kids to know they are not alone.

I want them to have some allies in this brave new world not of their making.