I don't think Hiraga would have a reason to hate Lovinia, since she stayed out of the fight. So as far as the war itself goes she would have no problem with her.

Maybe since Lov' was so stricken by most of her family dying, she might be trying to approach big sis as thus far Hiraga is the only family she has left? Hiraga would be pretty busy with banishing the leftover reaper spawns and trying to undo the damage to Earth, but in the meantime she'd let her get close, albeit she would not go search for little sis herself.