DLA, PIP or Attendance Allowance?

My Client has just turned 65 and is receiving DLA high mobility and low care from about 5 years ago. Her care needs have now increased and should probably be in the middle/high care DLA or if PIP receiving the standard or enhanced element.

I’m aware that if you are already on DLA when you reach 65 you can stay on this, but if she wanted to look at increasing her care component where would this leave her? Would she have to claim Attendance Allowance (but this doesn’t include mobility of which she is on high rate of DLA at the moment.)

(She lives with husband both get state pension and small occupational pensions, no entitlement to pension credit)
She also gets some Housing Benefit so I’m wondering what is the best thing for her to do to see how she would be financially better off all round? Any advice is much appreciated.

It won’t be Attendance Allowance. 

If they were under 65 on 08/04/13 (which it seems they were) they will have to claim PIP. 

(I think there may still be some areas where you can get DLA superseded but Manchester is not one of them)