I used the console and 'a.groups.insert(1,"nerd")' and 't.groups.insert(1,"nerd")' and it worked fine. Perhaps it is case sensitive and didn't like the capital?
I just do not see where a captial was used. But a case sensitive issue I also thought about.
the only MILF looking woman is the principal, and she's not a mother that we know of. MC's mom looks 30. Not exactly a MILF addict's wet dream
From how Maggie looks like, I would expect her in the early forties. If thirties, more very late and early 30.
Aside Larson and Maggie, there is also Anne from the beginning. Even first sex scene with the MC.
And MILF is a very loose term. For some it could be important that she just has kids, or how her tits look like. For others she that look old. But even old in this case could mean for a teen something different, than to someone who is 10-20 years older.
But I know women who are ~30 who looke like 16. Some 14 years old girls look like they are 20 years old. And in dating apps, women's age in the 30s/40s looks so different, that any use of age category for MILF is worthless.
Larson could even count as a GILF and I do not mean G = geriatric.