Take old SAT one time or just start with new SAT?

My daughter is a junior and we postponed taking the SAT as she hasn’t been able to put the time into at least practicing taking the tests. She is taking a new SAT prep class starting January. Would it be worthwhile to take the old SAT in January? She is planning to take the ACT in February and the SAT in March, and then based upon the results she gets, take one of the tests a second time in June. She doesn’t want to take the SAT in May as it will be at the same time as AP tests. ALso, I understand that the new SAT results won’t be out until after the May test is done.

As a junior too, I want to point out that either SAT or ACT will be a crucial factor to the college application next year.
Therefore, probably your daughter should know her “approximate score” by taking the practice test at least once.
She might get a pretty good score on the old SAT, like above 2000ish. Then it can be possible to increase the score (but not drastically) until January, and if she gets the goal score, boom. No worries.
But I know this situation is the most ideal one, and your daughter probably will have to take the new SAT or the ACT.
As my opinion, I highly recommend you to prepare for the ACT, because the new SAT will need to “assimilate” to the whole environment with an amount of time, as the changed SAT did in 2005, and there will be a lack of materials to prepare for new SAT compared to ACT, where ACT has an accumulated vast data of materials that you can access too. (Also the books.)
As myself, too, if I cannot get a goal score until the January test, I will start worrying about preparing for the ACT, not the new SAT.
Well, it is up to your daughter, but I feel the preparation for the new SAT would be pretty tough.

Take a practice test from the blue book to see how she will do on the old one. If she does pretty well prep between now and January. If she doesn’t do well skip the old one and prep for the new one.

The only problem with her taking the March SAT and then the June SAT if needed is that she really won’t have a lot of time to study once she receives her March score… At this point I would do as the above poster said take a practice test and if it’s a decent score go ahead and do the Jan SAT. Then I would focus on the ACT.