I'm not sure that we are all talking about the same thing here.
I interpreted the OP's question as after meeting the basic needs of your own family, do you put the basic needs of other kids next, or do you move on to giving your kids the next steps of toys, classes, nicer clothes, etc. Is that what is being asked?
Because I don't think anyone is saying that you don't feed your own kids first. I think we are talking about that next level of consumption, which are more wants than needs.
That one is trickier for me. I tend to think that something like music classes are a vital part of my kids' education. For others, those would be a big extra and possibly the source of charitable donations. I obviously don't want other children to literally starve, so I look for ways I can do both things.
Again, I think that there is so much more to do to help impoverished parts of the world than just give cash. I really think that shopping with your conscience and making choices to live lightly on the planet are a big part of dealing with the overall problem.
Also not sure that the word "deserving" plays a part in it for me. I think more in terms of, "is my kid having this at the expense of another?", as a guiding question. So for example, buying a cheap toy made in some slave factory export processing zone in Indonesia - is that supporting a viable economy for families in that country? I need to educate myself (and my kids) about it and make an informed decision that works with our ethics.
And I am certainly not perfect on this one, but it's how I try to do my part. I think being an educated consumer goes a lot farther than supporting one charity, personally.