I just get a new one on the paper, then I always shoot at least 300 rounds with many cleanings (about every 5 shots at first up to 25 shots at the end). Then I get serious about sighting in and seeing what she will do.
You also ask about pattern changing (I assume "zero changing), No, she shouldn't after the "break in" above. But be forewarned, any (read ANY) change in ammo may, can, and most times will change your point of aim zero... so if you sight in on an ammo and decide to change something (brand, reload, type of bullet, etc.) you must check your zero....
Of course some of us just "change things" to get to spend more time on the range <L>.