。
She's considering taking it to court as a last resort.
Literal
She [topic-は] last [genitive-の] means [as-として] court-matter [into-に] making [object-nominalizer-を] is-considering.
裁判沙汰 ('a court matter, a legal dispute') is an evocative compound: 裁判 ('trial, court') + 沙汰 ('affair, matter') — the second word is itself archaic, originally meaning 'sand-rinsing' (sifting through facts) and now used metaphorically for noisy disputes or ugly matters. To 裁判沙汰にする ('make it into a court matter') has a slightly disapproving, last-ditch flavor: legal action as escalation. ~を考えている ('is thinking about') with the ことを nominalization wraps the whole 'taking it to court' into a single object of contemplation. ~として ('as') frames 最後の手段 as the role being adopted.