I’m not sure. You’re very good at asking me questions I’ve never considered or researched before! I’m going to have to edit my personal info, downgrade my knowledge base. :)
It seems like she’s still not mature. Spiders of the North Woods (Weber) says females grow to lengths of 10 to 13 mm and males, 9 to 10 mm. Wikipedia says roughly the same thing, stating females are from 10 to 13 mm and males are between 8.5 to 9.5 mm. The Wiki article seems to have gotten its measurements from Kaston, who identifies the spiders by the outdated genus of Metacyrba. Oops- though, to be fair, his book was published decades ago (initially published in 1953; my copy is from 1972).
So everyone seems to be in agreement that the male is smaller than the female. Which means Peanut probably isn’t fully grown yet- she may not even be sexually mature, if her reaction to Mr. Mustache is any indication. Though I’m still leaning towards her getting ready to molt- the process is initially a bit uncomfortable, so she isn’t hungry and wouldn’t want to mate.
I suggest keeping him away from her until she molts or you figure out what is happening with her.
(Made public for anyone else who was curious about size and to show me actually using text sources.)