I had a mum acquaintance give me a Moses basket the other week and she was exactly the same, walked all the way to the bottom of the street carrying it for me.
I think people are just being kind because you're pregnant.
I wouldn't say a bouncer is too heavy at all. Ive just carried the hoover up the stairs. I know people who still pick up their toddlers, who aren't exactly light (I know mine isn't)
If it hurts your bump, it's too heavy, that's my rule of thumb