Well if they all like your DP then they'd have been on your side if she explained her remark and it was unflattering to him. You don't want to make a fuss. I understand that, but if the boot was on the other foot and one of your DP's colleagues said something similar to him about you, wouldn't you want to know he'd challenged it?
this could be anything but i would definitely clarify it OP. You could calmly say you didn't want to raise the issue in front of everyone but could she explain 'the face', as you can't work out what she meant by it. It could be that she is aware of male pride and wouldn't want to step on his toes as it were. You've got to clear it up though.
If she makes a disparaging comment about your OH, doff her one tell her she can stick her posh tumble drier. I hope it's all a misunderstanding though.