Rihanna was home with her 3 kids at the time an assailant targeted their L.A.-area mansion with gunfire — but her husband, A$AP Rocky, was MIA, TMZ has learned.

Sources with direct knowledge tell us … the singer was shacked up inside her house with the children she shares with A$AP — namely RZA, Riot Rose, and Rocki Irish — before all hell broke loose on Sunday afternoon.

The suspected shooter, Ivana Lisette Ortiz, allegedly fired off several shots from her vehicle at the residence … but luckily RiRi and her youngsters were not injured, our sources said.

The Los Angeles Police Department responded to a call of “shots fired” and spoke with the person who reported the shooting to get a description of the suspect. Officers quickly found the alleged shooter nearby and placed Ortiz under arrest. Police said a weapon was recovered.

Ortiz was booked into the L.A. County jail for attempted murder, and bail was set at a whopping $10,225,000 … which she has not posted.

Weeks before the shooting, on February 23, Ortiz allegedly posted a strange Facebook message about Rihanna, writing … “@badgalriri Are you there? Cause I was waiting for your AIDS 5-head self to say something to me directly instead of sneaking around like you talking to me where I’m not at.”