If it's a small filling and they aren't getting anywhere near the nerve, she won't need novocaine, and that's a good thing. Most pediatric dentists have great experience keeping kids quiet and still, and they have ways of explaining or presenting the info of what's about to happen in a fun and non-threatening way. I would ask them what they plan to tell her, and I would use the same words beforehand, or just reassure her that they will be telling her what's going on. The less you build it up, the less she will be anxious about it beforehand.
My son had a small filling without novocain, and it was so quick, he really didn't notice anything. The dental cleaning took a lot more time. I would tell her very little, and feel free to get info beforehand that will calm you as well as your daughter. She has no experience with this so she is not anticipating anything.
Going forward, if she does ever need novocain, you'll learn that they numb the area with treated swabs (like Qtips, sort of) long before a needle ever shows up. They also block the child's view or distract her so she doesn't see much.
If they recommend sealants for her teeth to prevent cavities, go for it! Then encourage really healthy brushing habits going forward.
Good luck and try to relax. I know it's difficult, but this is going to be harder for you than it is for her!