Complex sentence: Early in her acting career, she gained experience in English repertory theatre (in 1948, she acted in "Kiss and Tell" at Eastbourne with Tilsa Page and John Clark) before training at RADA.
Split into simpler sentences: Early in her acting career, she gained experience in English repertory theatre. In 1948, she acted in "Kiss and Tell" at Eastbourne with Tilsa Page and John Clark before training at RADA.