Right after I had my 1st baby, I was told that I should probably cut my hair to a short length because I wouldn't have time to get ready, much less tend to a long hair style with a new baby in the house.
I thought they were crazy. And the thought of cutting my hair off gave me flashbacks to the time when there was a little miscommunication with a hair stylist I saw in 7th grade. She took my hair from "just over the shoulders" with those feathered sides to just over my ears, in a short layered look. Everyone said I looked like Paul McCartney.
Anyway...I wondered how in the world a baby could take up sooo much time that basic personal hygiene would be tossed out the window. It's not like a shower and washing & drying your hair takes hours upon hours. Start to finish - maybe 45 minutes, tops? And as I found out, there was always plenty of time to get ready for the day even without going short. And the baby - she just hung out with me, smiling and cooing the whole time and hummed along with the dryer.
So, avoid the advice that you'll never have time to get ready in the morning once kids come and you should cut your hair all off so you don't need to spend time on it. Not true. Some of your best hair days are yet to be.