Grand Jeep Cherokee Hesitates from first to second gear

My wife says our 2002 Grand Jeep Cherokee very rarely hesitates as it moves from first to second gear (once every week at most). I’ve never felt the problem, but she says its happens when from a dead stop into 2nd gear. And she said there are no other times when the vehicle hesitates (fine in every other gear). No other weird noises and the power seems fine. Its an automatic transmission and I’ve had the fluid and filter changed recently. Any suggestions on what it is? Transmission? It is due for some new spark plugs… any chance it could be that? Appreciate the help!

Does the engine race when the hesitation occurs?
Did it start after the transmission was serviced?
For how long does it hesitate - an instant or seconds?
Hard or gentle acceleration?

Was the truck in an accident? (your name is jeepaccident so I thought I would throw it out there)

Thanks for the replies. No Accident. Wife says it races a little bit until it clicks into 2nd gear. Probably a few seconds where the RPMs are a bit higher than they should be.

Have you checked the transmission fluid level recently? I know you had a fluid and filter change recently but there are a lot of “Iffy Lube” places out there who can’t seem to get the fluid levels right. Underfilled, overfilled and no filled seems to be their mantra because it happens so often. Follow the directions in your owners manual for properly checking transmission fluid.