Never write for what's hot, write what you are burning to write.
The idea of the "lits" being hot is old news, they've been supposedly been hot, cooled down and gotten hot again. And as with every kind of book some people are making loads of $$ from them and others not so much, while others languish entirely. iLad lit, for example has already come and gone. Hen lit - they've predicted that heat coming for at least 3 years now but it's sure not showing up on lists and advances. (I have written some hen lit and mommy lit)
The trends sited - ethnic and YA chic lit have both seen jumps recently but is that market already full? Who knows?
Your title sounds like it you're in the right area and your heroine being 49 says hen lit, but hen lit usually has middle aged women issues (everything from caring for parents, grown kids, mid-life divorce, job issues, etc) A good example of a line aimed at this field is NEXT by Harlequin - great covers, good publisher push, freedom of storylines. And with Harl. you can still submit w/o an agent. Just a thought.
annie
Luanne Jones (Heathen Girls - MIRA - women's fiction and also dubbed lit light, btw, meaning crossover commerical/literary - and none of that means a danged thing unless readers like it)