Mike Lane wrote: So learn from them. No point listening to all the clucking hens here.
Ah, a condundrum. By posting here, Mike Lane becomes one of the clucking hens, in which case his advice is to ignore his advice.
Which is probably a good idea. John Wilder, in particular, has given a lot of helpful information. In any case, the OP has no way to evaluate the expertise of the climbers she is with and so has no reason to believe they are either more or less knowledgeable and reliable than the clucking hens.
If you ask for information from any large group of people, you will get a range of responses, usually from expert and useful to uninformed and possibly downright dangerous, with the distinctions often open to debate. At the end of the day, you'll have to make decisions based on what seems to be the most rational opinions and review those decisions as you require experience.
Here are my clucks:
1. Good for you for being nervous about the process. Most of the problems start when nervousness ends.
2. Weight differences are about more than being lifted. A belayer's hand strength is in some rough proportion to their weight. A light person belaying a heavy person will be more challenged than if the positions are reversed, so a light person belaying a heavy person needs devices and/or strategies that will provide enough friction.
3. Belay practices should be adapted to the worst-case scenario, and should not be merely adequate for what happens most of the time. Failure to understand this leads to dropped leaders and burnt hands.
4. Handling motions have to be practiced in controlled environments until they are absolute second nature.
Some elaborations:
Re 1: There seems to be a pendulum mental process in which people go from being fearful to complacent. It isn't all that hard to hold typical leader falls, which are relatively short, with relatively low fall-factor, and involve decent system friction. I believe there are quite a few belayers out there who would find they can't hold a much more serious fall but have no idea this is the case. This issue is compounded by the use of ever-thinner ropes.
Re 2: Different devices have differing amounts of friction. The highest-friction ATC-style device I know of is the Metolius BRD. It is also among the worst for handling, meaning that your management skills have to be especially good or you will short-rope the leader. At the other end, the original non-toothed ATC is inadequate for most of today's thinner ropes.
I think there is a lot to be said for using assisted-locking devices, especially when there is a weight mismatch for the climbers. In addition to the Grigri 2, there is the Mammut Smart Alpine and the Alpine Up. From a handling perspective, I think the Alpine Up is superior. If the ropes are fat, the Grigri is the only choice, however.
Unfortunately, listening to opinions, whether from internet poultry or local climbers---who may or may not be real live turkeys themselves---is of limited value. By far the best thing to do is to try to test out a bunch of devices (borrowed for the purpose, one hopes) in a controlled situation and see for yourself which works best.
Re 3: Wear gloves when belaying the leader. Pay no attention to the fact that not many people do this.