Jessy and her then Boyfriend Sasha (background dancer for NoA), had a baby together. This was not planned, but Sasha and Jessy were exited to get Cheyenne. Jessy never had the idea to leave the band, before and after the birth of her child. She thought that she can be ready like Nadja after the Birth and has already the support of her family to care for Cheyenne till to these days.
But the Music Company didn't believe that, and didn't want another mother in the Band, because the focus to keep the Band's success would have been disappeared. So, they instructed Jess to step away from the band.
They hid this reason, so everyone would think that this was Jessica's idea. when Jess went on her solo career, Jess couldn’t even sit together with her bandmates or see together, .
So, again the music industry did everything to do ridicules stuffs.
If you have the old 2002/3 Bravo, Yam Magazines you can read in every interview that she would have been happy, to join the Group again, and that (she) had no problem with it.