Linda,
Although the mother denies trauma, keep your antenna up and tune in
carefully.  This is a potential sign of abuse toward her.  If possible in
your conversations ask the question differently.  Ask "Has anyone hurt you,
even by accident?"  Some abusive men batter specifically the abdomen of
pregnant women, and their breasts after delivery.  Look for any other
bruises.  Give her opportunities to respond privately, just in case.  You can
let her know she can contact you privately if she thinks of anything she may
want to tell you.  Some women IF they are being threatened or abused will
contact you when they can--and the abuser is not around.
Of course abuse might not be involved at all with this mother--BUT keep your
antenna up and be ready to refer to a crisis counselor if needed.
Jane Bradshaw RN, BSN, IBCLC
Lynchburg, VA