British Family looking for 2nd helper

We are looking for a second helper to assist our current helper mostly in child care. We need someone who has strong mandarin and English skills, so they can help with our older children's homework and English learning.   Indeed, it is largely 'child focused' support that we require as the current helper does most the house-work and cooking. We have a 3rd child due in October, so there will be some baby care duties required as well although we have hired a maternity nurse for support in the first 4 months. Our two older children are 3/5yo. We are flexible in terms of 'start time' so whilst 1 August is ideal, we can wait if a strong candidate is available later. Ideal start time is obviously before our baby arrives, so latest October.