Teenage sensation Gill could barely believe her achievement after she led from the front and impressively held off the challenge of Reekie in the last 200m and seal her Olympic debut.
Gill lined up as a serious contender after breaking the 45-year European Under-18 800m record in 1:57.86 just two weeks after her 17th birthday in May.
Aware a top-two finish would confirm her Team GB place, she approached the occasion with a maturity that belied her inexperience – the significance of her achievement hitting her emotionally shortly after she crossed the line.
Second was enough for world indoor silver medallist Reekie to join Gill and Hodgkinson in the Olympic 800m.
Olympic and world silver medallist Hodgkinson will again aim for her first global title in Paris, this time without one of her main rivals for company after defending Olympic champion Athing Mu missed out on qualification following a fall at the US trials.
Hodgkinson, who took European gold despite battling illness in Rome, contested the 400m in Manchester as she aimed to sharpen up in the final month before Paris, and finished seventh in 52.22secs.
Another young talent claimed victory in that race too.
Anning, 23, has been in stellar form this year as she made rapid progress in the United States, breaking the 25-year British indoor 200m record in January in 22.60secs before running the third-fastest 400m by a British woman with 49.51secs in May.
She will head to Paris full of confidence after taking a commanding win ahead of Laviai Nielsen, who embraced sister Lina after crossing the line as they both confirmed their places on Team GB.
Lina Nielsen, who won an emotional bronze alongside Laviai as part of Britain’s 4x400m team at the world indoors in March, finished ahead of Jessie Knight in 54.81secs in the women’s 400m hurdles final as both athletes qualified for Paris.
In the men’s 400m, Dobson was untouchable as he confirmed his place for Paris.
The 24-year-old, who has won world bronze and European gold as part of Great Britain’s 4x400m quartet in recent years, clinched his first major individual medal with European silver this month and will join Hudson-Smith in pursuit of an Olympic medal.