Sometimes my friends will ask me for ideas for their online businesses. It seems that the most difficult thing for them is to think about a niche for their online sites. Most of my work at home mommy friends have niches spanning from health to food, with many of them picking the niche on parenting.
While it's good to pick a popular niche, what is more important is to pick a micro niche. For instance, the niche on 'health' is huge and very competitive but if you can think of a micro niche such as diabetes type 2 or kids asthma, it can then become easier to work on. Health niches can include joint pain relief, diet for seniors and even weight loss for teenagers. Basically, you want to be as specific as possible. There are also software that assist you in the selection process as you analyze the competition and searches for that niche.
There are lots of niche ideas that work at home moms can think of. Sometimes you don't even need to be an expert in that niche. Information in the web is vast and if need be, you can also order articles for your specific niche.