Maybe it would be a fish supper or whatever she could find with some careful late shopping: "You have to vary what shops you go to to get the cheap things," she said. Without a car, it meant walking miles with a pushchair. Her children looked well fed and cheerful but Ms Thomson, 33 had no doubt malnutrition was a big problem on the Craigmillar estate, Edinburgh.
Though only a couple of miles from the site for Scotland's first parliament by Holyrood Palace and surrounded by some of the most expensive housing in Scotland, Craigmillar, with its mainly pre-war tenement flats, is a sink of poverty. Steel shutters were being slammed down on the few shops that remained open.
Ms Thomson gets pounds 93 a week income support, including pounds 20 sickness benefit - "I get panic attacks and depression" - and pounds 27 housing benefit. It is not enough, she says, to pay for gas and electricity as well as feeding and clothing baby Chantelle, one, and her two other girls.
Her eldest, Corrina, 12, has reached the age where expensive labels matter in the playground: "She won't wear anything that she thinks will get others taking the mickey."
Harder, though, is when Ms Thomson can only give Corrina and eight-year- old Nicole a packet of crisps or sweets for their "play piece" at school when friends will be having lunch at the chip shop.
"I scrimp and scrape and I have to borrow money by the end of the week just to get me by." Somehow she manages. "There's a lot of bairns go to school without breakfast or without their play piece or anything like that."
Lisa, 19, is bringing up Declan, 12 weeks, on pounds 70 a week while studying accountancy at a further education college on the opposite side of Edinburgh, a 15-mile round trip by bus. "I don't starve or anything, but it's hard until I have finished my degree," she said with the optimism of a young person determined to break out of the Craigmillar poverty trap.
"I get free milk for the wee one but feeding us both is probably going to get more difficult when he gets on to solids." Lisa expected her tea would come from the chippie.
Jacqueline Peddison, pulling down the shutters on the chemist's shop where she works, said malnutrition was common on the estate. Either young mothers had not got enough money or it was going on drugs.
"The school dinner ladies will tell you," she said. "They see the kids who come up for three helpings. It looks greedy, but it's not greedy, it's just they're awfully hungry."