Hull had made six birdies and an eagle with Reid to beat Americans Stacy Lewis and Gerina Piller on Thursday but pulled out with asthma and a fever.
Reid fought back from two-down with a hole out for eagle to level the match in Illinois, but lost by one hole.
"I'm just really, really pleased I had a chance of even a point," she said.
Reid started the match on her own, with Hull being treated by a doctor in an ambulance near the clubhouse at the Merit Club in Gurnee.
According to event rules, Hull could have rejoined the match in progress but the 20-year-old said: "At the advice of the medical team, the best thing to do was to rest and get healthy for my team for Sunday."
In the other match, Jodi Ewart Shadoff and Holly Clyburn halved with Ai Suzuki and Ayaka Watanabe to leave England top of Pool B on five points.
Japan and Thailand share second on four points, with the USA propping up the pool with three.
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England's Mel Reid faced Japan's Haru Nomura and Mika Miyazato alone in the fourballs at the UL International Crown after Charley Hull was hit by illness.