the 1095A you input the % allocation youre taking on that particular return, not the other returns. You can allocate the % any way you'd like.

So on moms return, if shes taking 25%, you'd put her SSN and the 25% at the bottom of the 1095A on her return.  Same for everyone else, enter the 1095A and put their SSN/% at the bottom on their returns.