If the seeds sprouted they need to continue growing in a sowing medium or they fail. They are very tender perennials (more often annnuals) in zone seven and won't survive winter freeze. They have to go into a pot and maybe outside for a few more nights, but after that they'll have to stay inside.

T

Trudi's right. Every year I have babies underneath the mother. The seeds ripen and sometimes germinate in the fall. Unfortunately, they have never survived the winter. I don't sow my datura until March.

If sown now (indoors), they'd be fine if kept under grow lights through the winter?

It depends upon the amount of care and light you can give them. You're in zone six and won't be able to transplant them into your garden until May--that's six months from now.