Adopted sims, now some of the family tree has erased

Sorry the title is vague but couldn’t have many characters. 
Basically, two teen sims in my legacy challenge lost their mother so I had a distant young adult relative adopt them as caregiver. However, I also have Lumpinou’s pregnancy and family mod which allowed me to officially adopt them. 
I didn’t realise this would change the family tree, and now 3 generations have been removed from their side of the family. 
I did save my game so I’m willing to bet this is irreversible but it’s irritating me a lot as she isn’t actually the biological mother and I’ve been playing this legacy challenge for about a year now. 
if anyone has any ideas about how I could fix this, I’d really appreciate it.