AOB, assuming the person is your age, dont say anything right away, give it a few days and then when you go to be menachem avel talk about normal every day stuff. About a year ago, someone (never especially close with, but friendly) that I know lost her mother l”a, and someone said (which I thought made a lot of sense) shes young and doesn’t want to talk about her mother to someone who she was never close with, and it makes it a lot easier if you go when her good friends are there.
moish, someone who lost her mother when she was pretty young (not the same person that I was talking about in the comment to AOB) said during shiva, when she was clearly sitting on a low chair, wearing torn clothing, someone asked her what she was doing there. I know someone else who is a much older single who was very close with her mother and took very good care of her (which everyone knew). During the shiva, someone told her now that her mother was nifteres, she can get married. Yes, people say stupid things.
May there be no more suffering like this in klal yisrael anymore.