OP, with a fair wind, I finish the clinical doctorate next month, woop! I am 47. It is entirely possible. Out of the 10 of us on training, 3 of us are Mums. I was the oldest, but there were others late 30s/early 40s. A couple of late 20somethings. Average was I think about 33 at starting. Tbh the 20somethings were both incredibly mature, and being with all of them for such an intense time has kind of reverse-aged me. I've loved it.
It's taken me 7 years from the moment I decided I wanted a Life #2, but I had to do the conversion MSc, which you won't need to. I spent 3 years doing assistant roles.
That's the classic route, but there are some courses - e.g. Lancaster, Staffs - which do online entrance tests, and then interviews. The majority of the courses do, I think, shortlist via a points system, with points going for assistant psych/research assistant roles. But I do think all your experience sounds great, and I'm sure a lot of courses would take it into account.
As a pp said, why not apply this year, as a bit of a mock. Then you can see what experience you would have liked to have had, to be able to write about, and go and get that. And also lots of the courses offer feedback after shortlisting.
In terms of the actual clinical training, I think my age has almost entirely been beneficial. When I'm sat opposite patients, they see someone who has lived. I think it brings immediate credibility and assumed wisdom which the younger ones, maybe unfairly, have to earn. All my supervisors have referred to my age positively. The only downside actually has been in hospitals, with patients etc, everyone has assumed I'm a consultant, so have spent a lot of time explaining I'm just in training!
Go for it. Please. The NHS needs people like you. It has absolutely been the best decision I ever made.
PM me if you like.