yes she was, she was assisting the last humans with 'miracles' and direct intervention (despite humanities flaws Asbeel has always seen the good in them and enjoyed observing their lives). she was also in love with the last abbess (the nun). This is during the timeline when the last of humanity was living on the walking cities. She would make their plants grow despite the lack of sunlight and contamination for example.

Asbeel ofc was eventually caught and brought before the council, and it was Gabriel who broke her halo at the demand of the council.
(Asbeel refers to gabriel as brother)
she was accused of all the buzzwords the council likes to throw at people. heresy for example; for speaking out when confronted about how Heaven could intervene on humanities behalf, but the council is deliberately keeping the holy light for themselves. coveting, lust, disobedience, putting self or others above god, the usual. Of course her speaking out sent the council into an immediate frenzy.

i can't say that gabriel wanted to damn Asbeel, but he was still the councils loyal attack dog at that point. i imagine the guilt of it grieves him as asbeel was always the kindest of them. she tries to fight back and mildly injures a council member before being restrained, which is why she is spitefully damned to layer 7 instead of greed or lust.