Yes, both my spouse (the main applicant), I and 2 our children applied together in a single SET(O) application. Our initial Tier 2 dependent visas started in April 2015 (for 3 years) and were extended for another 3 years in April 2018.
In emails to my children, the HO also stated £630.00 in savings over a 90 day period requirements:
I am writing in relation to the application you have submitted for leave to remain under Tier 2 Dependant Child in the United Kingdom.
Unfortunately, due to the current circumstances surrounding COVID-19 and the latest government advice, for the safety of our customers and our staff, we have temporarily suspended the UKVCAS service locations where you would ordinarily take your documents to be scanned in support of your application along with submitting your biometric details.
We are keen for this disruption to have a minimal impact on our processing times and as such we are asking that you send us scanned copies of the following documents: -
The birth certificate for NAME
A bank statement displaying at least £630.00 in savings over a 90 day period (the end date of which must be no earlier than 31 days before the date of your application).
To the e-mail address WandSContingencyCaseworkDocumentReturn@homeoffice.gov.uk where we will be able to process your application to the next stage of our assessment which will minimise delays to your application caused by these extraordinary circumstances.
If you have any questions or concerns regarding this request, please direct them to the inbox listed above.