I understand your feelings about the recorder, Jane but a plastic Yamaha descant will be more accurately in tune and have better intonation across the range than any cheap whistle - and for about the same money.

You still need to listen and adjust to keep yourself in tune with others, but I will play recorder in preference to whistle in sessions any time, though my preferred instrument for sessions these days is harmonica.

I generally play flute and recorder (mostly tenor and bass) in our band. The flute is keyless and it's definitely not ET. I usually try to ensure I'm in tune with our fiddler as he is usually spot on. Needs a bit of work with the lip to do it, but it's got a smashing tone.