Kamala Khan has been extremely popular ever since her character was announced in November of 2013. Her book debuted in February 2014 and has enjoyed success since then as the first Muslim superhero to star in her own book. She took her personal hero's (Captain Marvel) old superhero name after developing shapeshifting powers when the Inhuman's terrigen mist spread across the globe after the events of the Infinity miniseries. She was created by Marvel editor Sana Amanat, who brought along writer G Willow Wilson, Adrian Alphona and Jamie McKelvie to develop the character.
No timetable on the show has been set, nor its connection to the larger MCU. Who knows if they'll even keep her as an Inhuman after how badly their show flopped and how badly positioning them over the X-Men in the comics turned out.
ADD-ON: During the Disney+ presentation at D23, Marvel also announced that She-Hulk and Moon Knight are also getting their own television series.