When I had my 2nd child.... my Daughter started attending Preschool. SHE also WANTED to go. She was really happy going to Preschool. Loved it.
It ALSO gave me time, just with my baby and I had had a c-section.
For me, this was a time that my Daughter had as HER own time too, interacting with kids her own age and having her own thing and routine. Not just being around me/new baby... and lost in the shuffle. It gave her time too... to be around friends and learning. Which she LOVED. I was not casting her off.... or banishing her. It was for her benefit too. Again, my daughter LOVED Preschool. I am a SAHM, and home all day. But it gave me time just with my 2nd born and time for my daughter to have positive interaction with others her own age... not just being around a tired M. and crying baby all day. It was an outlet for her too.
All around, it was a real positive thing. My daughter was happy. Not cooped up all day, having to revolve around a new baby.
My 2nd born, also had bad Jaundice after he came home, and for 2 weeks, around the clock, he had to be under the blue-light treatment at home. We could not go anywhere. I could only remove him from the lights, for nursing. It was arduous. And I had to take him to the Doctor and hospital about every other day. Meanwhile, my daughter was at her Preschool.... LOVING her time there. And when she was there, I would nap when my baby son napped. SO, by the time she came home (she was at Preschool everyday for half-days), I was rested. And then spent time with her. Quality time. She KNEW that.
Each situation is different. A Mom should not be critiqued... for having the eldest child at Daycare or Preschool, while a new baby is now in the home.
all the best,