Isolde is probably thought of as a bit shallow herself because of how wild she is. Friends are something she has plenty of and likes having, but she doesn't at her core necessarily consider her friends before she makes decisions. She cares super deeply for everyone she cares about, but she's such a creature of adrenaline and impuslve and emotion that she just doesn't think of "oh well if I poof for two years x y z people might get upset".