"I was thinking about what you said, and I've decided to give up my telly for a few months until I get back on my feet," she wrote.
I hadn't meant to guilt-trip her, I said. She'd been talking about the financial struggle to survive on benefits, and described the cost of a TV licence as "crippling'.
"There are people who would argue you should do without it," I said, before we discussed the need to feel part of society, to share in the things other people take for granted.
But this isn't the first thing Jenny's given up in the struggle to raise her seven-year-old daughter Sarah Louise on benefits.
Jewellery, including presents from her 80-year-old gran, have been surrendered to the pawnbroker – she won't see them again, she says. "I can't afford to get it back." She also sold clothes by the suitcase to a cash-for-clothes company. "I got £16 for three suitcases. I don't know how much they make, but there must be money in it."
These sacrifices are made because the choices are stark, the 38-year-old mum from Shettleston in Glasgow points out. "I can feed, bath, or heat my kid. I can't do all three. It is really depressing, and you do feel isolated from the world."
Ms Kiernan is part of a growing backlash against a political agenda which many feel is deliberately stigmatising and demonising the poor and those living on benefits.
She is a member of the Stick Your Labels campaign which aims to show the real stories and faces of people living in poverty in Scotland and challenge the stigma that can go with it. Members argue that Chancellor George Osborne and other Coalition Government colleagues are guilty of a gross distortion when they talk about people on benefits "living with their blinds down" while others head off to work.
The Poverty Alliance, a coalition of grassroots community groups, individuals, charities, statutory organisations, policy makers and academics, is making a series of requests to the politicians, charities and the media to promote a more balanced debate.
Peter Kelly, director of the Poverty Alliance, said : "We have seen an increasing hardening of attitudes to people claiming welfare, with more people wanting a tougher system of support. Unfortunately many views are not based on an accurate understanding of how our welfare system operates in practice, or of some of the realities of living in poverty, whether in or out of work.
"It is essential people base their views on welfare on the facts, not on myths and scare stories. With the significant changes that are coming to our welfare system it is vital that we protect people from stereotypical and stigmatising attitudes," he added.
Not all of those in the group are happy to be named – including "Lucy", who says she was abused by a bus driver for being on disability benefit. "He said: 'People like you make me sick. You've a bus pass, but there's nothing wrong with you'," she recalls.
In fact, she had a series of decent jobs until 10 years ago when she was diagnosed with the chronic gut condition Crohn's Disease. Since then she has been largely unable to work, especially as she developed osteo-arthritis as a side-effect of the medicine she takes. "We are not all scroungers, or lazy," she says. "I want to make more people aware that people on benefits aren't just sitting, doing nothing, we are making a contribution."
She volunteers regularly, she points out, but that doesn't mean she could work instead. "I could work when I was well, but the employer would have to not penalise me when I couldn't work. And they'd have to not mind that if I go to the toilet I could be there for two or three hours at a time. Or I might need to go every five minutes."
At times the Crohn's leaves her unable to move with the pain, she adds. But having an invisible, variable condition means she has twice been decreed fit to work by assessors working on behalf of the Department for Work and Pensions.
"My specialist went ballistic. I won one appeal and I'm appealing again. It's not a benefits system, it's an appeal system."
Her 15-year-old daughter also has to do without, while her partner – as Lucy's carer – is unable to work. "All you want is the best for your kids. But this isn't living, it's surviving and no-one would choose it," she explains. "The Sticky Labels campaign is good because it gives people the chance to put their side of the story."
Another group member, Ann Ramsay, who lives near Peebles, confirms she sometimes does conform to the Chancellor's stereotype. "My curtains are sometimes shut because I can't face the world," she admits. "My confidence is shattered. I'm 57 and I've always worked, but lost my job in the summer. Now there's very little work and even getting to an interview is unaffordable. I'm desperate for anything. But how are you supposed to look for work and go for interviews? You don't get enough dole money to do that.
"If the Government are trying to encourage people into work, why do they make it so hard?"
Although a scheme launched yesterday would give free bus travel to the short-term unemployed, the Sticky Labels group know that overall things are unlikely to improve for them with the autumn statement confirming real-terms cuts to benefit levels. However the debate over that change is raging and they hope they can influence it.
Meanwhile there is one happy development. Jenny has secured a youth work job, starting imminently, after more than a year of searching.