A lot of women work when pregnant, but her current "job" requires long hours, rehearsals, choreography, interviews, image consultations, photoshoots, filming, and a lot of other things that exhaust even someone in peak condition healthwise.The other two will likely have to pull more weight to fulfill obligations, while being at an unfair disadvantage, because of her choice to have a baby at this point and continue in the competition. Still, they likely see it as a better option than going home.