I guess it depends on how much you value your space. I have a really hard time handling clutter, and my rule is if it has not been used in the last year and will not be used in the next year, I do not keep it. Especially if I was moving, anything in question would be donated/sold/thrown away because the more items you move, the more your costs go up (bigger moving truck or more trips/gas, also just more hassle in packing and moving boxes).
If you think about the fact that she is not even pregnant yet- in fact, not even divorced yet- it could be years before she has a baby, if she even does. If she does, are your baby clothes gender neutral? Who is to say the clothes are her style? Is she ok with using a used breast pump (a lot of people are not). Also factor in the fact that a lot of baby items get recalled for safety issues or even if they are safe, better items come on the market... I would not hold on to those baby items for her. I would only NOT donate them if I knew FOR SURE someone was having a baby in the next 6-9 months or so and FOR SURE wanted those items (in which case- I would hand them the box and make THEM store it)