I think it was a smart move on your dogs part. Have you ever seen the damage a deer does to a car? They are not small animals and if she was protecting her young, then she meant business. Good thing here is that hd might have just learned a lesson and not chase any deer, a very good thing.
Misty- Samoyed Mix, Tannor- Golden Retriever CGC
Robyn- GSD CGC, TC, Midnite-GSD CGC,TC, Brennan-Golden Retriever CGC, Batman-Husky/Greyhound , Apollo-GSD