Its nice that your baby is young enough that you have some time to figure out exactly how you want to handle this.
When (if) you tell her no to the videos from the Org could you have some videos to hand her that are appropriate? Something like the "Baby Einstein" videos perhaps?
II mention those because they are popular even with the Witness moms although they are not religious at all.
That way your mom could have something you both agree on th show the baby.