As introduction, I have applied to be a LLLL, am a mother of 2 (ages 2 and 3)
still nursing toddlers and expecting #3 in March.

Bubbles--I babysat a bf newborn (6 weeks).  Mom easily pumped more than baby
could use. The breast milk always bubbled.  I rinsed, washed,etc. thinking
there was a soap residue but finally decided that it was normal.  Can't shed
any light on why, but baby was very healty.

Iron--To mom looking for natural iron supplements--Try Yellow Dock, Nettles,
Dandelion, Kelp.  I use these in various combos in tea form or pill.  All of
our iron levels are good even when nursing and pregnant.

Just a Note On Pumping--Many notes are posted "expressing" (no pun intended)
concern over not enough milk while while pumping or hand expressing.  Both my
childern exclus. bf until 8 or 9 mo. (no problems with iron, chewing,
swallowing).  Their weight kept my ped. happy.  But get me near a pump and my
milk supply suddenly disappears!  I am glad I did not depend on that to decide
if my kids were getting enough milk.