UK Settlement Visa for Indian Born baby

Hi,
I am currently a British Citizen attained after UK naturalisation by settling in UK through 5 year Tier-2 ICT. My wife holds a valid a UK Settlement visa, valid from Jan'2015 till Jul'2017. My baby was born in India by Aug'2015.

Since my wife holds a valid visa, I need to apply for UK settlement visa only for my baby.

Please clarify the following,

1. When I fill the Online application form at Visa4UK, should I fill as if my baby is filling it? If so, what should I mention for English language requirement? Reason for exemption from English language ability.

2. Can my wife sign the online application as mother of the applicant?

3. In addition of Online application form, payment reference, health surcharge and Form SU07/12, which APPENDIX should I fill as part of VAF4A?

Request you to highlight anything very specific to CHILD dependent for UK Settlement visa that would be helpful.

Thanks!