Is this unreasonable to ask of mil?

My Parents are visiting soon and I mentioned having them help unpack bc i am currently pregnant and have an over 8000lb shipment coming just a week before their visit. My in laws are coming soon after that and with a special needs child already unpacking alone may take me some time. I mentioned having them help as well bc even in a wheelchair my dad will try to help and in bad health so will my mom his parents are in good health and I'm not asking with help of big items. I mentioned maybe having his mom carry light items such as Teddy bears or pillows for me to help and he said she has a recent issue of not being able to grip items as if parAlyzed. I understand but then grew concerned over her holding and carrying my 15lb daughter who may still be in body cast. He mentioned her holding other grandchildren fine but it seems fishy she offers to help then I'm told she can't and won't carry light items but wishes to hold my much heavier child. would I be wrong for asking if she honestly can't lift small items to help that she not lift heavier more delicate things such as my child in a cast?! I'm not making them help unpack either before rude comments but she keeps offering to help using as excuse for us to pay their expenses and way here after they are broke from excessive spending and her refusing to work. They will be staying in our home so I'm not asking them to come here strictly to help or for a designated time just if we have spare time to make good on their offer to help.