Katie Price says her husband Kieran Hayler has been a great stepfather to her eldest son Harvey.

The 'Celebrity Big Brother' winner appeared on 'This Morning' with Harvey, 12, and her mother Amy to reveal what life his like with her child, who has various medical problems.

Harvey - whose father is retired footballer Dwight Yorke - has Prader-Willi syndrome (PWS), a rare genetic condition that causes several developmental problems and a chronic feeling of hunger, is on the autistic spectrum and has limited vision.

Katie has relied on her mother for help with Harvey's care over the years but Kieran has developed such a wonderful bond with her son she has felt comfortable letting her mother have a break.

Discussing the routines Harvey requires, she said: ''Mum did it for about 11 years, she was in the car with him but Kieran is so good with him, I said to my mum, 'Look you've done this for 11 years, you have got a life as well.' It's just me and Kieran that does it now.''

Amy added: ''Anything to do with his care plan, we go together. So at any one time we know where he is medical wise and education wise. Also we have passport for hospitals as well - so if Kate is working abroad, one of us will have to be here while Harvey's here so he keeps his routine in school.''

Revealing the difficulties involved in caring for a child with Prader-Willi syndrome (PWS), Katie explained: ''That's the worst one, I think ... With Prada-Willi he just wants to eat, eat, eat, if you're not looking he'll steal food. He'll just eat and eat and he's a big boy as well because of his thyroid problem. The Prada-Willi affects his behaviour because everything is about food ... Because he was my first, I don't know any different.''

Both Katie and Amy revealed that Harvey is doing really well with his reading and despite doctors warning them that his eyesight would not improve, Harvey can now read without relying on braille.

Amy, 62, said: ''He doesn't have to use a braille machine which is a real bonus because we never thought he would be able to see let alone be able to read.''

Katie, 36, added: ''And he knows his Makaton.''

The former glamour model will be cooking for her mum on Mother's Day this Sunday (15.03.15) to thank her for all her love and support and all her kids will be their for the lunch.

As well as Harvey, Katie has 19-month-old son Jett and seven-month-old daughter Bunny with Kieran and Junior, nine, and Princess, seven, with ex-spouse Peter Andre.

Speaking about her Mother's Day plans, the brunette beauty said: ''I'll be poisoning my mother on Sunday with my cooking! We've got a house full, we've got all the kids. It'll be good. It's a mad house, it's always a mad house!''