Streaky deciding to adopt Supergirl as his pet is perfectly in-character for a cat.
Of course it makes sense as to why someone as nasty and manipulative as Belinda is so popular when practically every other student in the school is also a petty jerk.
Supragirl arrives back in the present with Comet the Super-Horse, which she claims was loaned to her from Supergirl's older self in the 31st Century. At the story's end, Comet is stuck with Supergirl in the present, implying she'll have him with her until she properly goes to the future and loans him to Supragirl. This implies Comet is a Stable Time Loop and will be forced to endure relieving the same events for all of eternity. Ouch.
Even worse, Word of God from Landry Walker on Twitter confirmed this is exactly what happens with Comet.
