When does fierce become sassy?

I'm home again!

Saw fields of wild mustard flower and white plum blooms busting out, a couple rainbows, and bright sun through dark clouds driving back. Got almost 50 MPG. I'm getting better driving efficiently? I kind of like the drive, I have to say.

I had opportunity to observe an interaction that's got me thinking. Our unsupervised goats got to dancing on the hood of our car during forage time, and Joe insisted one of our daughters return them to their fenced pasture. Out-time needs to be supervised now, with the advent of this new caprine trick. Said daughter was frustrated at the perceived loss of goat and girl freedom, and spoke for this forcefully, and dramatically, without backing down. At some point I started to become uncomfortable. I appreciate hearing my daughters speaking up for themselves, what they believe is right, and for others. We coach them on this, and celebrate it most times. We've tried to be thoughtful about encouraging our children's original ideas.

But when does fierce become sassy, or become sassing your parents, as folks say down South?

I thank Joey for one particular development in my character. He speaks with confidence and certainty about what he needs and wants. I have learned to do that more myself, to have my needs (and certainly ideas and dreams) heard. I was more meek before I met and loved him. Have I also also become sassy?

What do others say about modeling assertiveness?