Lifting heavy toddler

So my son is almost 23 pounds. I’m used to lifting him, so I’m not worried about lifting him now that I’m pregnant. I’m worried about my nephew.

I watch him a few days a week and he is 10-15 pounds heavier than my son and is already a strain to pick up and put in his crib, high chair, etc. it’s made worse by the fact that I’m 60” and he is 36” and doesn’t support his weight when I hold him (he just turned two, and my son will usually wrap myself around my hips but he will not).

I’m going to ask my midwife of course, as I’m a little worried about lifting my nephew since it is already a problem for me and he is growing like crazy. What are your thoughts?