E.M.
Hmmm... Well, I think there are a few good ways to feel sexy.
1) If you like makeup but don't feel like you have time to wear it, pick a good lipstick, mascara and blush. You'll have that put together look in 1 minute flat and it will look natural.
2) Don't wear frumpy clothes! Choose a flattering Tshirt instead of an oversized comfy tshirt. Get some every day clothes that flatter in fit and color. No reason we can't look good even when we're going to the grocery store. It doesn't have to be expensive or fancy. I was the queen of buying tops 2 sizes too big. I simply bought some simple tshirts (from Target) in fun colors that fit and I felt so much more confident and sexy. A shirt or pair of pants with a little spandex in it gets you a great fit that doesn't bag out.
3) I agree, wear a sexy bra and underwear under normal clothes. Also, get a cute pair of sandals and paint your toes (it's almost warm enough). High heels and toddlers don't exactly mix, but look for something a little "cuter" than normal. Maybe a mid-height heel but with rhinestones? It will dress up your shorts, capris, skirts, pants... everything.
4) Buy a body spray that you like. My husband gave me one from Victoria Secret and I love it. 2 quick sprays on my belly and chest and I feel sexier already. (Plus he says I smell great!!)
5) Try to work towards a simple hair style that you can quickly do and that makes you feel good. Sexy doesn't have to mean 2 hours getting ready and a can of spray.
Also, plan a girls night out. I like the idea of trading off with a friend but you can also invite a friend over who has kids and have a slumber party. It's important to spend time with others, especially if you work from home.
Lastly, stand tall and look people in the eye. Smile at people and know that you are sexy, inside and out.
Good luck. I hope some of this speaks to you. It is hard getting back to feeling like you are sexy. I think it's the confidence and attitude that makes the impact.
Also, I found that putting my child in the shower with me sometimes worked. It may sound horrifying, but she would never want to be in the spray (more for me) and would find it so fun to stick her arm or leg in and then just play with the shaving cream cap (filling and dumping) the rest of the time. Also, I've put the little one in the tub without water (assuming you have a separate tub and shower in the same bathroom) with a few toys. If they cry, you just say, it's ok, Mommy just needs a shower... and let them work it out. I would also put a few books in the tub with her and she loved it. She got to where she would bring toys and sit outside the shower door and sing to me or babble about something. I always wanted to know where she was and I was never coordinated enough to shower when she was sleeping.
Good luck!!!!