i have to apologise - i thought she may have 52 - 54 speed, but that looks too quick ( a 52s hand time is proably near 53 for an auto time )
she is undoubtedly a 4'00.0 runner at worst & with various possible 400s, her 800 potential maybe
57.0 ->~ 2'01.4
56.5 ->~ 2'00.9
56.0 ->~ 2'00.4
55.5 ->~ 2'00.0
55.0 ->~ 1'59.5
54.5 ->~ 1'59.0
54.0 ->~ 1'58.5
53.5 ->~ 1'58.1
53.0 ->~ 1'57.6
52.5 ->~ 1'57.1
52.0 ->~ 1'56.6
53 auto or quicker looks too quick as it indicates current 800 ability upto the high-1'57s & no-one has ever claimed this for her
also, she may be quicker than 4'00, maybe 3'59 or even 3'58, so all those estimates above woud have to be quicker ( i can post those later )