What Would you do for a Job

Before I had kids, I knew that my passion was advertising. The first day I walked into my advertising agency, I remember telling myself, "this is it!" Of course, now that I have very young kids that demand a certain level of care and attention that I personally want to give, I have to kiss demanding jobs bye-bye. I am currently in the market for a part-time job. And while I don't have the luxury of being picky, my main dilemma is: do I look for a convenient job that might not necessarily be related to my experience or do I go for a more demanding job that surely fits my skills' profile? I feel like if I go after something I am not passionate about simply because it is convenient, that I am betraying myself; on the other hand, if I go for something more demanding I feel like I will be betraying my children. Someone please tell me there is a very simple answer to this!