Unaltered dogs do not belong in the dog park. If you plan to have her altered but are going to wait because of her size, try taking various obedience classes for socialization. The dogs are on a leash most of the times in classes, or at least they are more controlled than the park, so there is less risk of a fight. If you came to my park with an unaltered female, you'd have to deal with us dog enthusiasts running you out of the park for putting our dogs in a risky situation.