"I had a completely non-practical background and presented them with an English literature degree which was no use to them at all," she said. "I was also female - an unknown quantity - and 25, when their usual apprentices were all 16 or 18."
Edryd Jenkins electrical contractors in Aberystwyth, however, were ready to take the risk.
They gave her a job, let her study one day a week, and have just seen Grace win the Learner of the Year award for her electro-technical installation City and Guilds certificate at Coleg Sir Gar in Camarthen.
Grace, now 27, will become a fully-qualified electrician in the summer and is delighted with her career change. "Electricians get paid well, and the work is mentally very challenging and really diverse," she said.
"It's a well-kept secret. I think it's because they don't want girls on the building site - they want to put up porn, fart and burp, and not have women tell them to tidy up."
A report from the Equal Opportunities Commission last month said boys and girls are still being directed into typical jobs for their gender - even though four out of five girls would like to try out a non-traditional job.
There is a desperate need for skilled labour in the construction industry but fewer than 2 per cent of construction apprenticeships are taken by women.
At 5ft 6in and eight-and-a-half stone, Grace uses tactics to help her cope with practical difficulties - heavy items are lifted with levers, or propped up with wood.
Bad language on the building site doesn't bother her - "I've always sworn like a trooper" - but she won't tolerate girlie pictures on the walls. "I don't want to work with someone who's just been looking at porn," she said.
Once her male colleagues see that she can do the job, Grace says she gets a positive reaction.
But she admits that she only thought of working in a trade out of desperation. As part of her degree at Aberystwyth, she took a qualification in teaching English as a foreign language and taught adults in Italy after graduating.
Unable to find teaching work on her return to Wales, she was encouraged to consider skilled trades by her builder boyfriend.
Rejecting carpentry (too physical) and plumbing (too smelly), she chose electrical work, hoping the skills she had learned restoring an old Mini van would help. And there are additional benefits from an active job.
"You can eat what you like and you don't have to go to the gym," she said.