Potty training advice?

So I've noticed a lot of you have started potty training. We have tried a few times but not sure she was fully ready. This time I know shes ready cuz I've caught her on the potty by herself a couple times and she tells me she has to go on occasion.

We had our first full day today. I put underwear on her first thing this morning. Actually she brought the underwear to me and asked for them. With no accidents before nap time. Then I put a pull up on her for nap. She slept for quite awhile so it was wet. I put the panties back on her right after she woke up. Kept asking her if she had to go. She kept saying no. She wet herself.

I dont want my house smelling like pee. This is why I'm so reluctant to just let her sit in her pee.

Also we have a second due at the end of March so hoping we can have her fully potty trained by then. Although I'm scared once we have a new baby she will revert back. But I still think it's time.

Any and all advice would be apprecaiated.