<wanders delicately into Viva Strings, feeling that she doesn't really belong here>

Well, it's nearly Christmas, and I'm spending it with diverse relatives, amongst whom is an eight-year-old niece. She started cello lessons in September, and in anticipation of a mini-concert over Christmas, please can someone advise how you tune a cello? Do you turn the pegs on the scroll, or the little screwy things near the bridge? Is it best to start with the A string and work down, or C string and work up? What else should I know?

If it makes any difference, it's a quarter-size instrument, which (in spite of it being far too small for me and out of tune), I have managed to play all of the open string tunes from Cello Time Joggers 1 on.

Depends how out of tune it is. If it's very out of tune, you'll need to use the pegs in the scroll. If not, use the 'little screwy things' (called fine-tuners, or adjusters ). If you have a tuning fork or electronic tuner, or a piano for that matter, use this to tune the A string first, then work downwards. Turn the fine-tuners anti-clockwise to tighten the string, clockwise to slacken.

If it's very out of tune and you need to use the pegs, do be very careful. Turn the pegs gradually - a small movement makes a big difference to the tension of the string. If you need to tighten the string, slacken it first to avoid putting too much strain on the instrument. Tune the outer strings first (A and C), then the middle two.
Good luck and Merry Christmas!

Although if you are used to tuning violins you do hav to turn cello pegs quite a bit more than violin ones.

You could give your niece an electronic tuner for Christmas! They are a very useful aid to ear training. I use mine a lot (intonation still being something I find difficult - not because I can't hear the difference, but because my fingers often don't go to the right place!). I usually tune up using the A on the piano, then check to see if I am correct (almost 100% now). It's also handy on scales, especially chromatics. I never use it in my lesson though!

yeah, it's pretty much all been said, but the pegs should only really used if a string is more than a tone flat, or if the fine tuners/screws are in too far. If the fine tuners are screwed in too far, a good idea would be to screw them out about half way, and then tune the string up using the peg, so that it's easier to tune if it goes slightly flat. But yeah the pegs are only really used if the cello is really badly out of tune i.e. a whole tone or more flat =)