Would you call this?
 

ASA rules.

Pitcher stands behind the pitcher's plate. Brings her hands together. Steps on the plate while separating the hands, so MOST of the time, her hands are separated at the moment she touches the plate, sometime just barely. She then pauses with hands separated, brings the hands together, and pitches. OK, fine. Nothing here except an odd pre-pitch routine.

However, sometimes, the hands are still together for a fraction as she steps on the plate. In other words, she doesn't quite get them separated in time, even though she is obviously starting to separate them. She never did a quick pitch. She always paused with the hands separated.

Would you call this?

Ball or strike maybe, but not an IP

Ip
 

I may call it early and nip it in the bud; it's one of those situations you need to see to call.

This is a case where I would "mention" to her coach as he goes around me the next time that it would be a good thing if he made sure her hands were fully separated when she initially steps on. Suggesting that she's "close" to an illegal pitch for a double touch, and that "someone might not use the same good judgment as me, so far" seems to get them to have that conversation.

Even if that is the wrong (not pitching) coach, I've had good success with getting the message across to clean it up, rather than make the borderline call. If they ignore it, I then call the next more aggregious instance, and usually get the "well, he did warn us" reaction, more than the "that's tickytack" comment it might receive.

This is the approach I have used - also with good success

If you can call this one early with no one on base, I'd do so. Also, I'm not generally an advocate of telling coaches when someone's ALMOST illegal, but not illegal ... but I might in this situation.

Agree. It's also dependent upon the level of play whether or not I give a coach a heads up. In a rec league game or early in a weekend tournament, I would do so. But at a national qualifier, maybe not.

I agree with this approach. In particular the part I noted.

In my opinion, this is an example of a situation where a little game management can go a long way, as opposed to being a "rules nazi" (no intended offense to anyone reading).

I've seen too many situations where an umpire is technically, by the letter of the rule, making the right call blow up into a mess of a game.

By no means am I advocating being a GAGA umpire. It's a fine line that many umpires just haven't discovered the location of.

Agree with the Steves and Andy.
For the OP Q, answer generally no, as long as they end up separated for the pause.