Care Needs Assessment for Mother in Care Home

All about money
Any advice appreciated.

My Mum went into a care home just over a year ago and was self funding. Her money is now dwindling to the £23,000 limit and I have requested social services conduct a care needs assessment. They have now contacted me and given a date for the assessment. My questions are as follows:

My Mum has much improved in the home. The routine, having people around all the time has made her feel secure and she is happy. Prior to entering the care home Mum lived with me for 10 years but had deteriorated in her physical abilities and mental state in the last 18 months with me and this prompted me to look urgently for a placement. Now in the home she is happy and settled. Of course I am pleased and proves to me I made the right decision( Mum went willingly).
However I am concerned that the woman they assess there will be very different to the one a year ago and I fear they may say she needn't be there. Are they trained to look deeper than how someone presents at face value? I have kept all the old medical notes but will they take these into consideration as well. As I already care full time for another family member and am unwilling to go back to caring for two people will they take this into account?

Anyone who has been through this process and has any advice please reply. Thanks
You don't have to care for her. If they can't meet her needs fully at home ie as if she lived alone then they have to provide an alternative form of care.