Christmas family picture...

[Kileki]

So my family wants me to take our christmas family picture, and I'm not sure if i'm capable of doing so. Well I know I can take the picture, but with the lighting and the my lens quality (canon28-90), I'm not sure if it will even turn out good. I have a Canon XT with NO FLASH (smh, I know) and the lighting in the room they want to take it at (christmas tree room) has no good lighting. I know that trial and error is the only thing I can do, but do you guys have any advice before I try to take it?