Stella Mccartney's friends and relatives are concerned about the designer's health during her pregnancy, because she has been devastated by her estranged step-mother Heather Mills' vicious claims about her family. Mills - who is currently locked in a bitter divorce battle with the fashion designer's father, Paul - accused Stella of attempting to break up the former Beatle's marriage at any given opportunity in a series of U.S. and U.K. TV interviews earlier this month (Nov07). She ranted: "(Stella) was so jealous. Stella wasn't interested in her dad's happiness. I can't protect her any longer. She's done some evil, evil things." But 36-year-old Stella - who is seven months pregnant - is horrified that the former model and mother-of-one could make such callous remarks at such a sensitive time for the designer. A source says, "The last thing Stella needed is an attack on her like this in the final stages of her pregnancy. She was very upset and appalled that Heather, a mum herself, could be so insensitive at such a time. "Stella's kept a low profile throughout her pregnancy, but these awful claims have left her feeling really low when she should be excitedly looking forward to the birth of her new baby."