Thankyou so much Dragonfly2 and AAAAA.

You are both right. Heather is playing us off of each other. I know she is doing it but sometimes I will do anything for a peaceful life. I've talked to my husband about his stress levels and he admits that he needs some help. He's got an appointment to see our GP.
As for siding with Heather, Oops, I think you're right.

She tried laying the guilt trip this morning, saying that I was just like her dad! I told her that we both like respect!

Thankyou again. I will definitely take your advice on board.