If by "kid friendly" you mean something of the type sold in "bubble packs" -- take note that true FRS (what you most likely will find in local stores) do NOT do repeaters. Not even all GMRS bubble packs (if you find them) do repeaters. Granted, my information is a bit old, from units predating the 2017 reorganization of FRS vs GMRS. I have a pair of Midland units that reclassified as GMRS due to having three power levels, with the highest breaking the new 2W FRS limit, but does not do repeaters. I also have a pair of Motorola bubble pack which reclassified as GMRS because they DO have repeater mode.
That Retevis sale looks intriguing -- but I've already spent nearly $2000 on radio gear in the last few months (BTech GMRS-V2, Icom ID52A, Icom ID-5100A -- and the ton of support/options needed to fit that into my rust bucket [come on... a 9ft power cable, but an 11 ft control head cable? It's 17 feet from where the box is mounted to the battery!, and 15 feet to where the control head is mounted]).
Of the bundles -- the RB23 might qualify as the kid-friendly pair; water resistant, no front-panel programming -- configure them using computer software (set time-out timer so they don't just sit with PTT pressed and make noise at them -- you will have to change the channels to wide, the factory default is narrow (FRS compatible), and probably remove CTCSS tones from the basic channels; set desired tone for the repeater config/channel). The only thing they can do is change the channel, whatever you program the side button as [Monitor?], and PTT.
I'd probably pick the RA85 bundle. That model provides 30 additional "channel" slots into which one could program multiple repeaters with their CTCSS tones, even if they are using the same frequency pair. Nicer than having to carry a listing of repeater/tone around and manually changing configuration via front panel. Three power levels. Still has the problem that factory setting is NFM, not (W)FM, and they filled all channel slots with variations of CTCSS and DCS combinations -- I'd clear the tones, set all to FM, and clear out 31-60 unless I have known repeaters to put in.
The RB17 combo may be a bit perplexing for entry level... dual watch, front panel programming via a limited number of buttons. And Retevis NFM/tone combos preset... So I'd be clearing those out. I suspect these radios are designed primarily for Part 90 Land Mobile use which is probably mandated to be NFM.