I've always seen a difference between the 015 and the lactina.  I wonder what
would happen if she used the 015 at night and the lactina during the day.
 I'd be interested in the results.  The difference could be due solely to the
normal hormonal fluctuations over 24 hours, or even that she's probably
pumping more frequently during the day.

I prefer the 015 for a mother with a low supply or a mom  who is not directly
breastfeeding her child for any reason.  The lactina has several advantages,
though, the weight for one, the battery pack option, and the fact that it
cannot be contaminated by milk getting into the motor. Often moms want the
015 because they feel more comfortable using the one the hospital uses.
 Which, incidentally, is the same reason a specific brand of ABM is used over
another...the hospital wouldn't use it unless it was the best, would it???

I'm wondering if the frozen milk was contaminated before it was even frozen.
 There are several bugs that grow even in freezing temperatures.  How long
had it been stored?  Was the bottle sterile when it was filled?  Did she pump
directly into the bags, or was it transferred to the plastic bags?  Were
there any splits in the bags?  Was the milk layered from several different
pumping sessions?  She may want to hand express a few drops of milk before
pumping to clear the ducts. She may also want to be scrupulous about washing
her hands before pumping and making sure all her equipment is clean.  I'd
also look at the freezer's temperature, maybe it's too low or fluctuates too
much.  I've seen milk "go bad" fairly quickly when it's been stored in the
freezer door.  Would prolonged freezing break down the lactose in the
milk?--I've heard this somewhere....
that my two cents!