There are several different versions of the mod. Note - I can not do anything about the kissing looking weird for sims with different heights etc, as this requires to change the animations a LOT, and if it were easy i would think the sims team would have already implemented it Version Names
Remove the old one and place this in your mods folder unzipped** I added the fix to one of my downloads ( heightslidertoddlerfix), and will hopefully add it them all once I have more time. WARNING - A toddlerfix is made by vectorplexus for the old sliders by simmythesim. Only thing new is that the animation is no longer as funny looking. This is a height slider mod based on simmythesim first height slider.