i dont think your status have anything to do with your competence n performance.
and no, you r not required to declare unless you wanna claim the Childcare leave.
for me, i never declare that im a single mum, unless i think it is necessary.
just bcos you never say it out, doesnt mean you r not honest.
UNLESS, they ask you n you lie about it, tts dishonesty.
but you have no need to declare: hey im a single mum!
even when i go thru agency to find jobs, i just tell the agency i have a daughter, thus i want my working place near her CC, wont say im single or married.