For the last two weeks, his sage advice has been integrated into the hurdler's warm-weather training in South Africa where new ambitions have been forged following her failure to progress beyond the Olympic semi-finals.
The evaluation process flagged up a lack of urgency at the start of races. Yet the 25-year-old admits that the most effective lessons learned in 2012 came not from her mentor but from soaking up the approach of Great Britain team-mate Christine Ohuruogu.
The Londoner, who followed her Olympic 400 metres gold in 2008 with silver last summer, shared priceless insights with the Scot when both were engaged in the relay programme. The strength of her focus left an impression.
"Nothing seems to faze her," Child says. "She's a true champion but she's so matter-of-fact about things. She doesn't get nervous. It's all straightforward and you don't get to see that a lot of the time. She's very good at giving advice if you want it. She keeps the relay team together."
Child has set her sights on a regular place in the GB squad, starting with March's European Indoor Championships, and will get a chance to showcase her abilities over the flat 400m at the British International Match at Glasgow's Emirates Arena on January 26, running the distance indoors for the first time in eight years.
The move, she says, was Arnold's suggestion, in a bid to address a perceived weakness. "I wasn't going out as fast over the first 200 as I would have liked," she said. "Malcolm thought I should do indoors where you have to go out fast over the first lap because of the break. It's good practice."
She hopes there is better to come, despite breaking her personal best in her favoured event less than 12 months ago. At this summer's world championships, nothing less than a place in the final will satisfy her. Once that is past, attentions will turn to next year's Europeans plus the Commonwealth Games in Glasgow, where her current position in the rankings would leave her well-placed to repeat her medal gambit if 2010.
"When it comes to the Commonwealths, we lose the Americans and the Russians who are pretty strong in my event," she added. "The Jamaicans are very strong but there's no reason why I can't do well in Glasgow."
Reigning world triple jump champion Yamile Aldama has also been confirmed in the GB team for the Glasgow international.