You're too needy and have scared her away..
You got the kiss, and then you're like "Let's meet up!!"
You should of just played it cool and told her what you're up to, then perhaps tell her that it would be good to hang out again and do (insert activity) together...
"Texted her this morning (even though no response from day before) asking her to grab lunch this afternoon. She said she couldn't cause she was working."
This was a bad response from her. Asking her out after she has rejected your offer only makes you look chodey. Then then to make it worse, you texted her in the morning which conveys to her that she is your life and soul to happiness every time you wake up in the morning. It's needy bro.
Kissing her on the 1st date too is sometimes a bad idea. Can create buyers remorse, especially for online 1st dates...
Give it a couple of days and if she doesn't response, send her this:
"You never write, you never call, rent is overdue, and the kid's want their mum, what shall I tell them????
"If she still doesn't respond, don't waste any more of your time. Learn your lessons.
I know a divorce is hard and you're probably itching to find that woman figure back in your life, but play it cool and smooth next time..