An excerpt from the DVD commentary of the 1965 Doctor Who serial The Chase. (I've called William Russell "Russell" because Maureen does; it's his real first name.)
Peter: We should spend a little time talking about Jackie …
Maureen: Ohhhh.
Peter: … because she was consistent, she gave a marvellous performance, and of course she was with you right from the start.
Russell: Oh, she was wonderful. She was wonderful, she … Yes, she was, I mean, she was really remarkable, Jackie, because she had such delicacy.
Maureen: Yes.
Russell: She really was a very delicate performer, and in the best sense of the word. She was beautiful. And true. Always absolutely true.
Maureen: Always. And she was like a rock, you knew you could – that you could completely depend on this person.
Russell: Oh, yes. Absolutely, yes.
Maureen: I agree about the delicacy, yes, she was, she never did anything too much, or too little. She was very modern, in fact.
Russell: Very modern. Very modern. She was perhaps the most up-to-date of all of us –
Peter and Maureen: Yes – yes, yes.
Russell: – in a strange sort of way, I mean, looking at it now, you think "Oh, that, that's pretty good!"
Peter and Maureen: Yes, yeah.
Russell: And that lasts, all over the years.
Maureen: Yes. She was a lovely –
Peter: She was a lovely lady, a very sad loss.
Russell: Oh, very. Very.
Maureen: Oh, yes; a terrible loss. She was so kind to me. So were you, Russell.
Russell: Well …
Maureen: So kind to me. I was lost.
They digress into a discussion of how difficult it is to join an established cast, and how much it helps when people are kind.
Later:
Peter: Look, here's Jackie, giving one of the … I mean, she's, she's absolutely lovely in this.
Maureen: Smashing legs, as well, Jackie, I notice.
Peter and Russell: Yes, yes, yes.