HI Mama,
I'd leave her for a couple days for shorter days. Instead of 6 hours make it 2 or 3 and see how she does. I would not make the transition any longer than a week though.
As a daycare provider, what works the best is to take her in give her a hug and a kiss, let her know you'll be back at the end of the day, after nap, after lunch (be specific if it coincides with any of the daily schedule), and walk out the door. Don't give her sad face, don't hesitate at the door if she cries and reaches for you. This will only make it harder for her and for you too.
Kids are so resilient and also very perceptive. If you seem sad she will too. A good provider will be right there when you leave, either holding her and helping her say good-bye or close by to assist. And they will redirect and engage her in an activity so the upset of you leaving is short. I always encourage parents to call after a half an hour or so. I'd so much rather reassure them that their child is happily playing than have them sitting at work worried about how they're doing.
Also realize that she may seem fine when you leave for the first few days up to a couple of weeks, and then the novelty may wear off and she might have trouble with the drop offs. If it's a good fit though, it won't be long that she'll cry when you pick her up because she's having fun and doesn't want to leave!
Good luck~ What you're doing is really good for her!