Assault on a minor

In January this year, a friend of mine's daughter (17 yrs old at the time and my ex gf yaya for our mutual son) was assisting me with my son on a visit and also grocery shopping when my ex gf showed up and assaulted the 17 yr old. She left visible scratch marks on the 17 year old's arm and wrist and neck.

I took the 17 yr old to the Police station and she blottered my ex gf (who actually turned up at the Police Station 5 minutes after us)

The Police Officer did nothing as my ex gf started to shout and scream at myself and the 17 yr old, she was not even told to leave the room as she was being blottered

I also showed the Police Officer text I had received from my ex gf stating she would "kill the c*nt" and "I will not wait until she is 18, I am hunting her", calling the girl a "monkey c*nt", a "disease ridden monkey" and other such nasty text

My questions :

Should my ex gf have been arrested for assault of a minor on the spot ?

Should the Police have informed DSWD ?

Should my ex gf have been allowed to stay in the room as she was being blottered ?

The girl is now 18 and wishes to file a case against my ex gf for the blotter. Can she get the assistance of PAO to help her file ?