To me, it seems like Beth (rightly so) recognizes how much she and Randall are not in tune with what’s happening with their daughters, particularly at a point when she’s acknowledged that she’s not at her best.
MMV, but I didn’t read it as a direct response to Tess questioning her sexuality. It was more of a red flag to her partner that they’re not the Randall & Beth parenting dream team they thought they were. Hence, calling family.
There was still no fallout from Kevin’s accident as far as WHY their daughter wanted to run away. We’ve seen Beth & Randall show significant cracks in their home life as the cost of Randall’s quest for living up to his mythical fathers. Quite frankly, I’m surprised it took Beth this long. It’s probably the most natural & realistic reaction any of these characters have shown since the show started, IMO.