Well, you know your child best, but a course designed for 8+ might have some skill and behavior expectations that a just-turned 7-year-old might not be able to meet.
Does she already help you in the kitchen? Is she a competent reader? Can she read fractions? Would you let her handle a knife on her own?
Are you near a Sur La Table? Their kids' classes often have options more appropriate for the younger-than-8 crowd.
Mine will be 8 and the only thing she really struggles with is fractions, but we've been working together in the kitchen since she was a toddler. And she's had her own knife since she was 4. I know she would adore an AG cooking class, but she's also a little immature for her age (executive function problems!) so we've been cautious about allowing her to participate in classes like this. (Also, our W-S store doesn't really have a classroom area like the SLT does, so I feel less confident that she'd be able to manage the skills & behavior there than SLT.)
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Liz
DD (3/2010)
"Make mistakes! Get messy!" - Miss Frizzle