ILR granted, Flr(m) applied but query from HO

[JTF2007]

Dear Guru's

I have applied for ILR (10 year long residence) in 12 August 2013 which has been approved on 13th Jan 2014 Brp and documents have been received on 16 Jan 2014 also I have applied Flr(m) for my spouse and my 6 year kid born in UK.

I have received a letter from HO asking me to send my passports and 6 months Bank statement which I have already provided along with other documents back in 12 August 2013, my Spouse entered UK in August 2007 as student dependent.

My questions are:

1, Is it some serious scenario or I am just panicking.

2, My ending balance of Bank statement is not great (£600) as I am working only 20 hours although not receiving any sort of benefit but I have checked there is no specific financial requirement before july 2012 (old rule) or am I assuming it wrong.

3. HO gave me only 14 days to respond so please guide me through.

waiting in anticipation

Regards

[JTF2007]

help plz prompt reply will be highly appreciated.
Thnks.