Since there’s a shortage of senior royals due to Kate Middleton and King Charles battling cancer, it looks like the family is turning to non-working royals such Princess Beatrice. According to an insider, Prince Andrew’s daughter “has been asked to fill in for Kate and do some appearances for the monarchy this summer.” Beatrice, 35, “would love for it to become a permanent situation,” added the source. “Beatrice is comfortable in the spotlight and would be overjoyed to become a working royal.” For her part, Kate, who announced she has cancer in March, is feeling “pressure” to return to her dut…