Darren Galsworthy said he "couldn't have done better" when choosing Anjie as a step mum for Becky.
Speaking fondly of the pair's bond he said "almost instantly there was that bond, that connection, I couldn't have got a better mother for Becky if I'd have tried".
But he said, since Becky's death he had seen his wife - and Nathan Matthews' mum - who suffers from MS, quickly deteriorate.
Talking to Ian Axton Darren described the relationship between Becky and Nathan, and said the pair didn't often spend time together, Matthews instead getting on better with Becky's brother Danny.
He said Becky's attachment to Anjie had lead to his choice of gravestone for teen - depicting a figurine "with a baby girl hung around the neck".
"I thought that was so appropriate, where Becky was concerned because she spent half her life there [with Anjie], even in the later stages."
Watch Darren Galsworthy's full interview with Ian Axton here: