посредница bedeutet auf Englisch

intercessor [intercessors]▼(one who intercedes)
noun
[UK: ˌɪn.tə.ˈse.sə] [US: ˌɪn.tər.ˈse.sər]

intermediary▼(an agent acting as a mediator between sides to facilitate agreement or cooperation, see also: mediator)
noun
[UK: ˌɪn.tə.ˈmiː.dɪə.ri] [US: ˌɪn.tər.ˈmiː.die.ri]

mediator [mediators]▼(one who negotiates between parties seeking mutual agreement)
noun
[UK: ˈmiː.dɪeɪ.tə(r)] [US: ˈmiː.di.ˌe.tər]

middlewoman▼(The female equivalent of a middleman; a female intermediary)
noun

negotiator [negotiators]▼(a diplomat, moderator)
noun
[UK: nɪ.ˈɡəʊ.ʃɪeɪ.tə(r)] [US: nɪˈɡo.ʊ.ʃɪeɪ.tə(r)]