Horsebacking riding w/ five-year-old

[KatieCharlotte]

My youngest would love to go horsebacking riding on the beach, but she would only be five or just turned six. I see that Carnival horseback riding excursions have a minimum age of six, but the local companies in Montego Bay allow five-year-olds. Am I crazy to even consider it? She has, of course, only been on ponies. Most of the group horse rides I've taken in the US were on very slow, gentle horses that follow in a line no matter what the rider does, but I don't know what to expect on this ride. I'm sure she will still weigh less than 40 lbs then and together we weigh under 160 lbs, but it doesn't sound like they'd let us ride together. Has anyone seen small children on this excursion? Can you recommend one company over another for safety issues?