So parent and child have conflict every time parent wants child to get dressed.
it's been so warm the last few weeks. Maybe she's too hot in her clothes? (in which case, just a sundress maybe - I'm sure it's too early in the year for burning to be very likely)
Or maybe she would prefer to choose her own clothes? Some children like to be offered a choice and they reject the ones they don't like.
Some children are perfecty happy to BE dressed, they just don't want to GET dressed. It's a passing thing, but you can save everyone hassle for the weeks or few months while it lasts by a) give up on pyjamas and just put tomorrow's clothes on the evening before. b) with some children, it actually works best to wait until they are asleep, and then slip on some easy-on clothes - wait until they've gone really floppy, but catch them in the first half hour of sleep when they are out for the count.
I know families who've had a few days where the child didn't want clothes and the parents just said "ok then" and played at home and in the garden until the child was happy to have clothes again.
I've met others where children refused to wear anything in the house for a while, but if you got in the car to go somewhere, they were perfectly happy to put on t-shirt and skirt/trousers at the same time as climbing in the car seat, and then shoes and socks as they climbed out of the car at the exciting destination.