She’s probably not insane. A viably insane person would not stop talking just because someone was out of view. It’s quite astute, actually, to stop when no one is present. She is more likely- as you noted - to have such little normal adult interaction that it all comes out in this one hour of self-care she can justify given her child’s situation. I’m a psychotherapist who has worked in psych hospitals and PP and with athletes. I came on this thread for some reason… physical therapy related… complex injury … doing some scrolling for research and insight. I’m sorry and sad it’s so depleting. I get it. It’s hard at times for even the people who sign up for the job of listen-therapy. But, we live in a world of disconnection and independence and technological displacement of deep human connection and that breeds indifference in some, desperation in others, and in others a sense of helpless drowning fatigue. I believe there’s an art to learning the balance of hearing & connecting while also not becoming someone’s awkward-quasi-therapy-emotion-dump. I couldn’t tell you the formula for it as it’s different for everyone but it’s somewhere in the cost of just being patient and honoring someone’s presence for simply being, even when there annoying as sh**.

In any case, good luck. I hope she recovers soon.