I can't find out when this lady was born, or if she is even still alive.
The earliest date that I can find on her is 1968, when she exhibited in Belgium. The earliest book that I can find, which she did illustations for in 1972. She was also co-author for a few books (all children's books) and the last date that I can find, for a book, is 1989.
Seeing as one of the ladies, interviewed about her own exhibition and who talks about her fondly, was one of her students in primary school and that particular lady has already retired, I am thinking that Jaklien (pronounced Sha - clean) is probably no longer with us.
I have exhausted nearly all of the hits on google.nl and .be and this is the best that I can do, Stu.