Unusual request for a private image purchase

I have a former colleague who now lives in the states and she has asked me if she could buy an image I have taken recently.
The unusual nature of the request is that she has asked if I would supply the image electronically on licence to allow her to get it printed locally.
I have contacted the company I usually use for canvas prints and they advised me that they have a sister company that dispatches to the US and so I can provide the canvas. When I have let my potential purchaser know they'd still prefer the image electronically under licence.
I doubt the image would make anyone millions, but I am somewhat uncomfortable with the idea of providing a high res electronic copy of the file. The fact I used to work with the person helps, but still... I don't know them well enough to be sure that I am not being fleeced. A licence is all well good, but it needs to be legally binding and I have no idea where to begin with this.
Just to add to the spice - currently all my print sales are contributing to a charity fundraising initiative I'm involved with. So the money for this purchase would be very welcome!
Any opinions/advice?
The unusual nature of the request is that she has asked if I would supply the image electronically on licence to allow her to get it printed locally.
I have contacted the company I usually use for canvas prints and they advised me that they have a sister company that dispatches to the US and so I can provide the canvas. When I have let my potential purchaser know they'd still prefer the image electronically under licence.
I doubt the image would make anyone millions, but I am somewhat uncomfortable with the idea of providing a high res electronic copy of the file. The fact I used to work with the person helps, but still... I don't know them well enough to be sure that I am not being fleeced. A licence is all well good, but it needs to be legally binding and I have no idea where to begin with this.
Just to add to the spice - currently all my print sales are contributing to a charity fundraising initiative I'm involved with. So the money for this purchase would be very welcome!
Any opinions/advice?

Present to her, in writing a Single Non-exclusive rights of use licence that spells out the terms under which she can reproduce the image and how many times. Charge her your usual print free.
And then it’s down to the age old problem of trust, exacerbated by the distance involved. She could be selling it down the local farmer’s market and you just wouldn’t know but that’s the way it is with providing digital images to a multitude of outlets.
You could attach the licensing details to the file but I’ve experienced very few printers who check it.
And then it’s down to the age old problem of trust, exacerbated by the distance involved. She could be selling it down the local farmer’s market and you just wouldn’t know but that’s the way it is with providing digital images to a multitude of outlets.
You could attach the licensing details to the file but I’ve experienced very few printers who check it.

I have no experience at all of selling images to other folk but I would say if you are uncomfortable with doing it then I would advise saying No. You are feeling a little beholden to her because you have worked with her in the past but the image is yours and should remain yours and she should be happy with that. If she isn't - 'tough'!

Its always a difficulty selling anything digital on line. A lot of photos can be downloaded, copyrights removed and digitally altered .... I have an Etsy shop and offer digital downloads of both my artwork and photographs, I have a clause that states for personal use only any commercial use must be passed back for perusal and costing, but dont see how I can enforce it. I think an earlier advice to you to sell it at a price of unlimited plus a basic art fee or stick it out and say only via your print company, if she really wants it then she will accept your terms. Mixing friends and business rarely works. Be honest and keep your principles.