As an ex Bulldog breeder I can assure you that a dog or pup that has never seen or been exposed to the great outdoors will find it over-whelming initially. Just go slow, plan on it taking weeks. I would start right at the door to the outside, put her on a blanket on your porch.

Go VERY slowly!

No experience with Lyme... well my wife had it.

One of my rescue dogs was the same and it was particularly severe as she'd been hit by a car. We had her sit by the door so she could look outside and then bought her into the backyard. Without the distraction of traffic and other people/animals it was easier than taking a walk. Finally, we could walk her outside but she was still very reactive and would just lay down on the sidewalk when it got overwhelming.

Like Salti says, it takes a LONG time to acclimate.