Ms Waissel, a former pupil of Heathfield School, Pinner, worked in her mother’s dress shop, DNK, before auditioning.
She went on an RSY tour in 2002 and the family is often seen at ladies events held by Pinner synagogue.
Her father Maurice said: “We think she could be more successful than Stacey Solomon, but they have a completely different style.
“Reaching this level she is living out her dream. And she’s in it to win it. I sing and play guitar. She gets her music from me and her looks from her mum. We want all Jewish fans to vote for her.”
Ms Waissel last year featured in an online web series “Green Eyed World” about making it in the music industry - which she made under the name Katie Vogel. She has also recorded in the US under the name Lola Fontaine.
Lawyers had to free her from a deal with Chamberlain Records before she could appear on the show.
Facing Lord Sugar this year will be Alex Epstein, 26, from Whitefield, Manchester, a former King David pupil.
The ex-Haagen Daaz ice cream manager has been on Birthright and joined an Aish trip to New York in 2002.
He also went to Bury and Whitefield Jewish Primary and was made redundant from his job in corporate communications. Steven Mintz, who teaches Jewish Studies at King David, said: “He was a very likeable student, but very individualist and determined. If we’d have known then that he go on to be an Apprentice finalist, we would have said he had all the right attributes.“
Former housemate Rachel Lewis, said: “The first time we ever went out together was to the JSoc freshers’ event at Tiger Tiger. He’s a sociable and he seemed to know everyone.
“Alex would know what a kosher chicken was. We have laughed about that. Alex hopes to make a better impression on Alan Sugar than Michael Sophocles did. I’m sure he will — he really is a very good Jewish boy.”
JFS old girl Melissa Cohen, 27, is also likely to know her way round a kosher chicken. The former buyer for Tesco claims to have “single-handedly increased Tesco’s share of the kosher food market to 75 per cent”.
Joy Stefanicki, 31, from Portsmouth has been working as a “PR guru” in Birmingham. She “loves Israel” and has visted many times. Although the family are not very religious, Ms Stefanicki has considered making aliyah. She has also worked in New York and done volunteer work in Peru.
Sister Pippa has been rousing support on Facebook, creating the Joy Stefanicki Appreciation Society. Friends, many of them in Israel, have already posted messages of support.
Former Ilford Jewish Primary School pupil Jamie Lester, 28, is hoping to use skills from his former career as an estate agent to impress Lord Sugar.