Hi Ron! You should say 'Es un placer conocerla' since you're meeting a woman. 'Conocerle' is sometimes used in very formal contexts, but 'conocerla' is the standard and most natural choice.
That said, it depends on the level of formality.
Es un placer conocerte. - More casual and friendly (used with tú).
Es un placer conocerla. - More formal and respectful (used with usted).
Since you mentioned wanting to show great respect, Es un placer conocerla is the better choice. But if the situation is more relaxed, Es un placer conocerte works fine too.
hope this helps :)