The phrase "already frail" is correct and usable in written English.
It can be used to describe someone or something that is weak or delicate, emphasizing that this condition has existed prior to the current moment.
Example: "After years of illness, she was already frail when she entered the hospital."
Alternatives: "previously weak" or "already weak".
Grammy Sue, already frail, may be imperiled by his outbursts.
Still, the prolonged insecurity weighs heavy on his already frail nerves.
Every day he must face his daughter Nesma, already frail from a poor appetite.
The demographic hemorrhage was felt in spreading ripples, and the already frail population of Central Africa was further weakened.
Frances Seward, already frail, was undone by caring for her family and by the assassination of Lincoln.
She had trouble breathing and could not keep food down, which worried her family because she was already frail.
Republicans, contending that the C.F.T.C.'s rules threaten to crimp an already-frail economy, have pushed to reduce the agency's budget.
It is here that poverty squats on the many rural towns and villages that comprise Irbid; the weight of poverty taxes the already-frail infrastructure, its relentlessness reduces talk of clean water and healthy food to mere rumor, and its indiscrimination leaves an indelible mark on everyone and everything.
When the harsh living conditions of the jungle began to take their toll on the the already-frail child, the commander sent him for treatment at a health centre.
Already psychologically frail, she retreated into shock, losing her sense of time, even of who she was.
According to the Centers for Disease Control and Prevention and the Environmental Protection Agency, reports of Americans falling ill from drinking tap water are rare, and mostly involve people who are already in frail health.
