Yes I would, do both. Allow my child to be fed and feed another.
I'd definitely prefer it to be someone I aslo had a bond with - whether it be blood or love but if I needed donated milk I'm all for screened milk from strangers. Having worked in a NICU where EBM mixups are treated like a bodily fluids contamination kinda influenced that though.
When my sister had her third bub 6 months ago she wanted to not bother with BFing so I offered some EBM to give her little guy some antibodies to start with - she was horrified.
It's actually quite common place up here and widely accepted. All the indigenous women do it, so have helped the cause immensely.
Arcadia your playgroup sounds pretty amazing.

