was with Jane when they were children?

I can't find anything in the book.

So till the age of 4/5 they must have met under the supervision of her mother, who must have guided her well.
It must have been Mrs Woodhouses duty to invite Jane over at that time.

We ahve information about Jane's childhood in CH:20;

Jane became their guest, paying them long visits and growing a favourite with all; and, before she was nine years old, [......] an offer from Colonel Campbell of undertaking the whole charge of her education. [........]and had lived with them entirely, only visiting her grandmother from time to time.

Jane is away for long visits. She is like a family member to them.
When in Highbury it must have been for short visits, and not left to Emma to invite her, but Miss Tayor, and they must have been together under Miss Taylor's supervision.