It is inevitable that Marie Wiik will return to Lalande. I think she has no other place she feels she can go and be part of something.
For all we know, FRK may have been fired from her job at the florist weeks ago. She can't hack regular work, regular time schedules, or regular adult responsibilities. It was probably too overwhelming for her, as usual. Her employers were likely frustrated by her obstinance and mood swings, failure to make arrangements their way, and FRK's insistence on using her own unique "floristry" methods. It's very strange that FRK's last video was a wedding bouquet demonstration "at home" and that she brought the flowers from work.
For all we know, the embrace and promotion of Lalande by FRK's mother, Gunnvei Grice, may just be a ploy on her part to move her daughter along. They have a complicated relationship and they both must get on each other's nerves. It's like with the good people of Haworth. They can only take so much of FRK before they pay her persuade her to leave.