There is the
Pro-Tech holster, but it's crap. There are also a number of generic ankle holsters that might work: the
Daltech Force holster and the
Chengyuan holster. I am not sure if they are any good though.
PS: My comment regarding the Glock 42 or 43 as a home defense gun for the wife was more geared toward getting her a Glock 19 or 17 dedicated for that purpose. There is really no need to go small for a home defense gun.
PPS: As for the rest of your home defense plan, there is no need for chest-thumping here. No, you won't defend your home with "a dozen or different handguns calibered in either .40 or .45". It doesn't even make sense in the first place to say such a thing. A 12 gauge is a good "defend the fort" weapon, while a single high-capacity handgun would be your backup. Both would need to stay loaded at all times.