Lady Macbeth's attitude toward Macbeth in Act I is of love, but a lack of respect. She describes him as
"fear[ing his] nature;
It is too full o’ the milk of human kindness(15)"
thus justifying her desire to "unsex" her. She feels that Macbeth's goodness will stand in the way of pursuing the witches' third prophecy -- which is to have Macbeth become king. She clearly believes that the only way to obtain power is through "foul" means, which, according to her, Macbeth doesn't possess, as can be evidenced when she states:
Art not without ambition, but without
The illness should attend it.
Lady Macbeth does fear that her husband is too loyal and compassionate to "catch the nearest way" to the throne (1.5.18). She says, "What thou wouldst / highly, / Thou wouldst holily; wouldst not play false / And yet wouldst wrongly win" (1.5.20-23). She knows that he doesn't want to cheat or deceive anyone, but he does want something that isn't his (and there's no way to get the throne without doing something deceitful). He's just a little too nice for her taste. So, she beckons him home, and she seems confident that she can manipulate her husband, "pour[ing] [her] spirits in [his] ear" so that she can convince him how easy it will be to take the thing he wants (1.5.29). Evidently, she finds him fairly easy to control.
When Macbeth does arrive home, Lady Macbeth seems a bit concerned that he might give everything away by neglecting to act and look innocent. She reminds him, "Bear welcome in your eye, / Your hand, your tongue. Look like th' innocent / flower, / But be the serpent under 't" (1.5.75-78). When he suggests that they'll need to speak further about their plans to kill Duncan, she assumes control, saying, "Leave all the rest to me" (1.5.86). In other words, she just wants Macbeth to focus on pretending everything is normal; she will do all the heavy lifting in terms of plotting and planning. This makes it seem like she feels that he is a little unreliable; she wants to retain control because she doesn't seem to trust him to get everything right.
(And, to a certain extent, she's correct about him. As we see in the next act, Macbeth has trouble keeping it together. He forgets to leave the murder weapons in the room with Duncan, and then he refuses to return them. He panics about not being able to say "Amen" or sleep peacefully again. She's also more than a little wrong about herself and what she can handle, too, as we see much later in the play.)
When the play opens first showing Lady Macbeth she has received news that her husband has been given the new title Thane of Cawdor. This news shows the true nature of Lady Macbeth and her feelings for her husband. She instantly begins calculating a plan to advance her status. In her calculating she takes into consideration that Macbeth may not be man enough to follow through. She has to use Macbeth by manipulating him to get what she wants. She does love Macbeth, and because of this love, she is able to covince Macbeth to initiate her plan to kill Duncan. Her love is definitely twisted and selfish. Towards the end of the play, however, she has no sense of love, it has been turned to guilt.