It was Howard/Darcy, With Darcy as Tony's Mum Maria.
I remember a specific scene where a group goes to the past to convince Darcy to return to present day, I believe Howard was out or in the Lab, and Darcy was taking care of kid!Tony.
I think the group included Jane, Steve, Dr Selvig and maybe others that I can't remember.
Darcy was explaining that she belonged in that time, despite knowing how she'll die.
I think Edwin Jarvis was there, but I can't remember.
Any clues? I know it's probably not much...
Thanks anyway =)