I think knives are possibly the tool that a lot people have trouble sharpening. I remember when I used to offer a sharpening service one guy turned up with loads of blunt kitchen knives - apparently when he'd needed a sharp knife he just bought a new one!
Now, I don't know who does the cooking in your house, but Vanessa has to 'remind/ask' me several times to get a decent edge on the kitchen knives for her before I remember to do it. I sharpen my workshop tools probably every day or at least every time I use them. Why can't I get into the habit of doing that for her? A little touch up every week is what they need - perhaps I'll start doing it 1st thing on Monday mornings!
I've never got on with a steel and those gadgets they sell that you pull the blade through are hopeless.
You can easily and cheaply make a knife sharpener like this:-
Buy a sheet of 800 and a sheet of 1000 grit wet-or-dry paper (about 50p,80c,€0.6 each).
Cut a 1½" (4cm) wide strip off each sheet (about 11"-28cm long) and glue them to either side of a piece of softwood about ½"(12mm) wide. Spray mount adhesive is good for this.
Form a nice ergonomic handle.
Note the grit numbers on each side.
I'm not going to tell you how to sharpen but use the rougher (800) grit first then the finer (1000) and use it dry.
If your knives are really knackered try making one with rougher grits.
You could use up the spare paper to make up some more as presents for friends who have trouble with knife sharpening.