Chris Brown's Baby Mama Diamond Takes Kid to Disneyland Amid Paternity Lawsuit

Chris Brown's baby mama, Diamond Brown, took their daughter to Disneyland after taking the girl's father to court ... and it looks like mother and child had a blast.

Check out these photos Diamond shared from her Disney day with her 4-year-old daughter, Lovely Symphani Brown, on Mother's Day.

Diamond and Lovely are cheesing for the camera in Fantasyland ... snapping selfies with Mickey Mouse ears as they wait to ride Dumbo the Flying Elephant.

The Disneyland outing comes amid Diamond's legal battle with Chris ... as we reported, she dragged him to court last month ... filing a paternity suit just days before CB welcomed a new baby with his current girlfriend, Jada Wallace.

Diamond says Chris acknowledged paternity in a voluntary declaration ... and she's asking the court to award her legal and physical custody, while proposing Chris have visitation. She says Lovely's lived with her in Los Angeles since birth.