Take a paper clip, straighten it out then bend it in the middle so both ends almost come together and you will have something that looks like a hairpin that can be used by your sister. A small needle nose pliers to do this will help.

We are kinder to our plants in England. We use small
stakes and soft plastic metal ties.

If she is a master gardener I would have thought that she would have enough inteligence to solve the problem herself instead of having to ask somebody.

She's a Master Gardener, not a Master Engineer Rogi, LOL

I think she uses them to support seedlings to keep their teeny, tiny little leaves from bending over and touching moist soil to prevent rotting. Personally, I use cocktail toothpicks - either primary or secondary use- in my case secondary use is a preference. For the bigger stuff here in the good ole USA I use bambo stakes and all plastic electrical ties. Also I see that some of the GOY members graduated from that world renown university- WHATSAMATTA U.

Oh, I might add that I attended the New York City branch of that university-Wossamotta U! YEAH! GETTA LOAD OF THAT!!! "We are kinder to our plants in England." LOL! SAY WHAT? Welcome to GOY Colebay.

Gawd blimey, I've read the answers here and get the distinct impression that in two of them, a couple of wasps were having a bit of a sting... somewhat unnecessarily. Still, takes all sorts I guess.. but both might be interested to know that hairpins are invaluable for propagation purposes.

Welcome from me too Coleybay.

Amazon has 65mm hairpins available in the UK, perhaps they do in the States?

I checked, yes Amazon has them.

And welcome from me too, without the sting!
There are plenty of plants which may be propagated by pinning down a piece of stem into a pot of compost and allowing the thing to root. One often scrapes the underside of the stem where it touches the soil to help roots form.
Unless of course that is counted as being unkind to the plant.

I have also used hairpins ... and paper clips lol ...
but I am not English ! :o)

Welcome from me too ...

When I want to layer a plant, I use small wire cutters to cut up metal coat hangers into 4-6 " lengths and bend in 1/2. You can also buy reels of wire in GC that you can cut to size as you want them