Rae is indeed quite a bit older than Claire but pretty sure she's not 30. Like timeline wise she did graduate college and made up with her old friends. But Misaki's death was still very raw for her and she overworked herself likely in part due to the grief. So at most, I'd put her at 23-24.
Which is still 9 years older but that should be a better estimate. Not counting og Rae Taylor's 15 years that is.