Seem to be a lot of authoritarian parents on this thread (do as I say or face extreme punishments).
As someone who aims for authoritative parenting instead, here’s my take.
Read ‘How to talk so kids will listen’. It has really great strategies and examples of just the type of situation you’re describing.
Set extremely clear expectations - away from the point of stress ie at a time you can both talk calmly and positively. Explain the problem and come up with solutions together. And I mean really clear - what does eat sensibly mean? ‘Sit at the table and use your spoon. Thank youm’
Put tools in place to support - probably some kind of visual timetable or checklist giving her some responsibility for completing the task.
Make it being done well feel good for her. If it’s not done, give one warning and then follow through on the consequence (probably some kind of her time wasted later in the day because she made you late earlier). No need to shout or threaten. Just be consistent and calm - so also, build extra time into routines at the start so she has a bit of time to fail without it causing mega stress. Practice makes perfect.
And never make a threat you aren’t 100% prepared to carry through.
Good luck!
(Fwiw I’m a teacher who uses this approach at school successfully & have 2 very lovely teen & pre-teen dc who understand that when mummy (or any responsible grown up) says something, they blooming well do it. We can discuss it, but they’ll do it.)