Kendra Wilkinson feels her critics are rooting ''so hard'' for her marriage to fail.

The 'Kendra On Top' star, who exchanged vows with former NFL star Hank Baskett six years ago, believes their relationship will always have ''ups and downs,'' but insists she is in it for the long haul.

The 30-year-old beauty said: ''Marriage is a lifetime of ups and downs. And Hank and I welcome the challenges that will continue to help us recommit our lives to each other and look forward to growing as partners for years to come.''

The former Playboy model, who has son, Hank Jr, five, and daughter Alijah, 15 months, with the gym owner, also hit back at new rumours she is preparing to dump Hank, 32, and has been mistreating him recently.

She told UsMagazine.com: ''Honestly, what kind of mother would invite that kind of chaos and pain into her home?

''I am, though, sad to see anyone root so hard for a marriage to fail. I don't feel the need to defend the authenticity of my marriage, my family or my business anymore.''

The couple have worked hard to get their marriage back on track after Hank was accused of cheating on Kendra with a transgender model while she was eight months pregnant with their daughter.

She recently said: ''Our marriage is amazing right now. We are working on it every single day. It's a lot of work, 24/7, but we're both willing to put that time in and really stick it through. We're both in it for the long run, and we both have goals, and they're both the same.''