Thanks  MummaBear and EVERYONE...
Ever since having my son, I do not pass judgment on moms having difficulty with their kids, though before I did.  I know all to well what it's like to lose my grip of the end of that rope!  My neighbor is right above us in an old private house, so all noise sounds like it's right in the next room.  The girl definitely is throwing tantrums, but I believe it stems from the fact that she is sorely unhappy.  I really can't blame the mom because she is doing the best she can in her own situation and I know that it's not her choice to live this way... which is why I hesitate to say anything because she will definitely get on the defensive.  She does not get close to anyone, though we do talk as she comes and goes, albeit however brief.  Also, as you say, I am sure that we make noise down here when they are trying to sleep because we are early people and they are late people (sleeping schedules).

The other issue I have is with her dogs.  She has two of them and they are walked on our property, but they do not clean up after them.  We have tracked the crap into our home a few times (just when Gabe was learning to crawl) and I flipped out.  It's such a shame but I refuse to let my son play on our property because of it.  I've complained to the landlord recently only because we actually gave bags to the guy who was walking them, and with my own eyes, I saw that he did not use them.  I hesitate approaching her on any of these things because I don't trust myself to keep my head and I don't want to create a war zone.

I want to thank EVERYBODY for their input.  I like the idea of just continuing to sooth my son when he gets upset and to explain more to him about the girl and to emphasize that she is ok.  This is turning into a lesson of how to deal with unpleasantness, in general.

Hi cheleinkal...
I wanted to tell you that it doesn't seem as if the mom is hitting the child all the time because, as I said, I hear everything like it's in the next room and I don't hear that... but the mom does get impatient and yells at her.  Most of it is because the girl doesn't want to leave the house in the mornings and mom is late.  Then it's because the girl doesn't want to go to bed and it's late... like 11pm.  So, I hesitate on this because it doesn't sound like abuse, just a frazzled mom.  I really like your idea of telling him that I'm lucky to have him as my little boy, because I really feel that way... though we don't always express that to them.  thanks!

Crystalmoon... thanks for the advice.  I do whatever I can... I will keep the girl company when she starts screaming  in the hallway when mom is out walking the dogs (another issue).  But mom is not the type to get close to anyone and I do not want to push myself on her.  I hesitate to talk to her about it because I know that she will view it negatively and I don't want to create a bad living situation for any of us.

sorry I meant more not my guidance MY bad LOL