By Mark Jefferies Her latest theatre show has not gone to plan, but Sheridan Smith is still smiling, as her TV work earned her £1.1million last year. The talented star is currently starring in West End musical Opening Night but poor reviews and ailing ticket sales have led to the production ending two months early on May 18. But some critics pointed out it was the script that was to blame and even Sheridan’s skills could not save the production, so her credibility remains intact. Sheridan, 42, who has spoken frankly about her mental health battles, runs a company to take in cash from her telly…