Here's the (probable) first in the title "Girls Sonic 3 Piece PJ Set". First because it is specifically mentioned to be 'for girls'. But really, as with everything almost Sonic, if it fits literally anyone boy or girl could wear it because Sonic & friends are for everyone.
This set has a blue short sleeve sleep top with modern jumping/peace sign Sonic line art. The effect on the art is that it fades from yellow to aqua to pink as the line continues. The shorts with it are pink but they're probably also plain/no Sonic element. The pants are black & use line art scattered all over. It has line art of Sonic and Amy Rose along with a star bumper. So, a good item for Amy fans too. This set appears at Target in winter 2021, and should be about 17 dollars which is an ok price. It may be in the girls/teens area, but it is also likely to be online at their website.