Daycare teacher here!
There are a lot of things you can do to help your daughter ease into daycare. Probably the most important is to make sure she doesn't know you're worried about it, you fret and she's going to fret right along with you. If she hears you worrying about her then she's going to have a reason to worry. Talk about it, let her know what will happen and what she'll get to do at daycare. What part of the day will she be there for? If you can take her right at the start of an activity, like circle or art, it'll be beneficial, even if it means dropping her off ten minutes early. I saw you mention that there would be days when she doesn't have to go, if at all possible try to keep a consistent schedule. Going to daycare for a week, missing the next week, then going full time the next makes it hard for kids to adjust. If your husband's schedule allows for him to keep her home for a week see if she can still spent 2-3 days at daycare.
Try to visit ahead of time so she can see what it is. Telling a 2.5 year old about daycare would be like talking to me about complicated math, I haven't a clue what you're talking about but I'm going to nod because I do know what some of the things are.
When you do visit talk to whoever will be there when you drop off about how they do things. The best method for unsure kids, at least that I've found, is you hold hands/hold the child while you relay any information to the teacher. Say goodbye, give a kiss, hand her off and have the teacher walk to something to distract and then you walk out. Just make it quick, like pulling off a bandaid.
If her first day is great, be prepared that her second day might be harder but then it'll only go uphill from there because she'll realize what's going on.
If you have any questions I'd be more than happy to help you. Daycare is a big change, I like to make it as easy as I can.