Sure, you can summon a T-Rex, but the monster does not have all the abilities of a PC, including feats, class abilities, spell effects and magic items. It is just a T-Rex and as such is a quantifiable component. Giving PCs a spell that could equate to +20 Str, stacked on top of...
Alignment determines the effectiveness of some spells and magic items. If she is acting in an altruistic manner (or seemingly altruistic manner) for altruistic purposes (or seemingly altruistic purposes), she can still get by with being chaotic neutral. As just a few examples off of the top ...