Aladdin has a most complicated plot; indeed, sometimes it is hard to follow it. There are several twists in the plot -- some unexpected. Aladdin may well be an only child. Aladdin and his mother are very poor, but being poor doesn't seem to make any difference. Aladdin, however, is a very strong character. He resolves several problems that would seem quite difficult to resolve. You might not be able to picture Aladdin in your mind's eye, but you know what he would do.
So many plot elements contribute to his getting the sultan's daughter -- she is a princess. He pursues her and goes to a lot of trouble -- including his mom -- to win the sultan's daughter. He becomes a great military leader.
Note, too, that we the readers know many things that Aladdin does not know. We know the uncle is a "false" uncle. In the end, though, we know the story has / will have a happy ending -- "the Wonderful Lamp." What keeps you reading? Probably all the twists in the plot.