Advice needed- blissey

I think the best answer is no...because you never know when you're going to hatch a chansey. If you do, then those 80 candies will come in handy as you'll want to max out that one.

Any Blissey is a good Blissey, I think(and I love that you call her blessey as she is a blessing for any trainer not battling her). Sure, she is a comparatively weak Blissey, but powering her up to a level where she can get into gyms usually makes sense. I wouldn't power her up to use as an attacker unless you really really need an attacker. Blissey is defender #1 and should be used as such regardless of moveset. If you have plenty of strong defenders then maybe wait for a better Chansey. You may also just use her as is. Level 26,5 isn't that bad, but it depends on your meta. If she can get into gyms at this level, then by all means just use her as is.

To the prof!

I would use her on attack as-is, at level 26.5 she will still be able to take down multiple opponents, just a bit slower. If you really like it you can take her to 30.

She's a very solid attacker. If you have enough time, she should always be your number 1 attacker with that moveset!

Yeah I think I'd be tempted to use her as an attacker too, and save candies for your other Blissey, or a new one.