Apple Watch se battery life

Anyone having problems with battery drain. I bought my wife an se watch for Christmas and the battery don’t even last a day. She takes it off charge about 7am and before 10pm at night it’s flat. I’ve got a series 2 watch and it lasts for about 2 days. I’ve unpair her watch and reset it as a new one but nothing seems to work have read a few people are having the same issue so is it the iOS 7.2 that’s the problem as my s2 is on iOS 6.3 and I’ve never had a problem with the battery