Do YOU believe it's OK to love her?! Because if you do, that is what matters, really......maybe you're wanting reassurance that it is from T herself, but what is important is that YOU believe it's OK and that validation comes from within you, not without, from her. Of course it's OK to love!
Your T is wanting to be neutral and positive in email and not 'do therapy' in email, I think, as well as maintain boundaries.....reassurance of love being OK, of it being OK to love her, even those simple words are going beyond the boundaries she set and she needs to be careful of her boundaries and not let them get blurred.....