I'm about to turn 50 and agree with several of these.
Tap dancing and ballet - yes! Took up both last year.
My DCs are still preteen, so will be at home for a long time yet, but they are more independent year by year. Me doing ballet and tap comes from DD doing both too, so I would say encourage them to follow their interests and maybe you'll find new ones too.
I've been lucky so far, no sign of menopause, but fat is harder to shift, aches and pains are more frequent, look after your body, oh and use spf on your face.
Along the same lines, you are not too old for long hair, make-up, short skirts, black nail varnish or whatever suits you and you like wearing. I disappeared into frumpsville for a while in my late 30s, I'm not the height of fashion now, but I grew back my hair, learned a lot about hair and make-up etc in my 40s and am a lot more confident in my appearance now.