A.K.
Hello A.
My kids are also two years apart. My daughter would cry or say "baby crying" loud and often whenever my son cried. It was like this for a few weeks and then she got used to the baby crying and ignored it. We would notice that if she was doing or talking about something she was interested in she didn't notice the crying at that time anymore. Then eventually, she pretty much stopped. Now she only says it occasionally like once a week. My son's 5 months now.
I think my daughter needed to get used to the fact that babies cry and sometimes you can't get to them right away or can't help them right away. My daughter legitimately thought she was telling us something we didn't know. After all, if we knew the baby was crying why weren't we doing something about it.
Hope this helps. I think you just have to wait this out. Good luck.