Re: "But isn't it weird?"
I gotta say... even as someone who has nursed 2 babies to a year and never once found that 'weird'... that if I look at my now 2.5yr old and imagine nursing her I find that insanely weird. I'm not at all saying I think other people are weird for doing it. I couldn't care less who other people nurse but I can totally see why someone would think it weird.
Having said that.. asking the question is a bit rude. But on the other hand, if they don't ask, then they won't know that the mother doesn't find it weird.