Rachel was comatose the whole time Jean and Scott were raising Nathan in the Askani Future. So it was 11+ years of guilt for Jean and Scott. Both of them expressed remorse for how they treated Rachel. She was the one who inflicted that on them but they would never had gotten those years with Nathan without her.
It would expect Rachel & Jean's relationship to be awkward now since they haven't really spent that much time together. But after spending all that time feeling guilty for the way she treated Rachel, it make more sense for Jean not get bitchy with Rachel.