My husband and I frequently take friends sailing, and this generally includes people who have been sailing before but who need directions--they don't instinctively know what to do. Before we get near the slip, we give everyone a job and clear directions.
This past year I got new docklines for my birthday. We measured them and spliced them (actually, for the small price of a bottle of rum, one of our boat neighbors spliced them) and now all one has to do is grab the
line and put it on the
cleat--it's always the right length (yes, they are connected to lengths of chain so we can take up length or let it out if we need to).
I agree with the other poster's suggestions to practice with your family several times. Everyone will be much more comfortable if they know exactly what to do.
When we're coming in with friends aboard, I am at the helm and my husband is at the bow, ready to grab the windward bow
line. Friend one (in this case, the one with more experience) is mid-ships, ready to grab the aft springline. Friend two is mid-ships on the other side, ready to fend off of the piling if necessary. Once the boat is secured with those two
lines, we go about the business of grabbing and securing the other
lines.
When it's just my husband and I, I am at the helm and his position depends on the wind direction.
For your family, if you haven't pre-set the length of your lines, I would do that. Particularly when we're coming in in less-than-ideal conditions, docking is MUCH easier--no having to take time tying the line--just drop it on the
cleat.
I'd also encourage your wife to take a sailing class/learn more about sailing (Doris Colgate - Sailing: A Woman's Guide...excellent book, written in ways that make sense to women. Yes, women and men think differently). The more comfortable she is on the boat, the better. Plus, God forbid, if anything should happen to you, she needs to be able to maneuver safely. If nothing else, she should know how to drop the sails, start the engine, and
radio for help.
Have a great time!