When I was younger I read this fantasy series involving two siblings who find out they are wizards. Their parents are involved to some extent but I think they are mostly learning from their uncle (maybe? a slightly older gentleman at least). There are some things that I remember specifically including: that there is one scene in which the mother tells one of the children that they should always treat homeless people with kindness and give them any money they could because sometimes homeless people were Angels who would watch over you after showing selflessness; in one of the books there is a detailed description of the hanging gardens of Babylon in which they are residing at the time. Another thing I remember is that wizards were capable of drawing perfect circles and lines because of their use in many spells. I am pretty sure that it was a trilogy, or maybe when I read it there were only three books written, I think I read them sometime between 2006-2010.

When I was younger I read this fantasy series involving two siblings who find out they are wizards. Their parents are involved to some extent but I think they are mostly learning from their uncle (maybe? a slightly older gentleman at least). 

There are some things that I remember specifically including: that there is one scene in which the mother tells one of the children that they should always treat homeless people with kindness and give them any money they could. This is because sometimes homeless people were Angels who would watch over you after showing selflessness; in one of the books there is a detailed description of the hanging gardens of Babylon in which they are residing at the time. Another thing I remember is that wizards were capable of drawing perfect circles and lines because of their use in many spells. 

I am pretty sure that it was a trilogy, or maybe when I read it there were only three books written, I think I read them sometime between 2006-2010.