Tie2 PBS dependants extensions, prime applicant on ILR

Hi,

This is Ramakrishna currently holding ILR, Wanted to quick ask the below question regarding my wife and daughter's Tier2 PBS dependent extension based on my ILR. Currently they are in UK and their visa's are due to expire on 12 Feb 2021.

Wanted to understand the funding requirements.

Currently We have a funding issue to file our Tier2 PBS dependent visa extensions : Guidance copied from GOV.UK website : You must have £2,205 if you want to bring your partner and one child with you to the UK (£945 to support yourself plus £630 for your partner and £630 for your child).

1. Do I need to maintain funds of £945 for myself also with my dependants maintenance fund of £630 each, in total £2,205 for a period of 90 days as I am on ILR?
2. Can we show funds from abroad account?
3. Does it need to be joint account?
4. If we don't have joint account, can I show my wife's 90 days of bank account statements along with my 90 days of UK bank account statements to show the total funding requirement?

Could you please help me with information, as it is really essential and urgent.

Could someone help me in this regards, anyone who helps with this information will be highly appreciated.