"The lads such as Tom Vaughan-Lawlor and Robert Sheehan have done so well for themselves after being on the show," the 24-year-old told the Herald.
"I think it is easier for male actors in Ireland at the moment -- there are more roles for them and they get noticed quicker. It is a tough market with the female actors."
Former catwalk queen Susan, who many fans will remember as one of the hopefuls in season six of Britain and Ireland's Next Top Model, trained in acting at New York's Lee Strasberg Institute.
The Malahide beauty has been taking advice from some of the show's big names to help develop her acting career, especially co-star Aiden Gillen, who played Debbie's gang leader boyfriend Johnboy before he was killed off last series.
She said: "Aiden was fantastic with me. I was just a young actress coming in and he really helped me. He would say, 'make sure you are comfortable with that and don't be afraid to tell them what you think'."
The departure of Gillen's character from the show signalled Debbie's descent into prostitution and further abuse of drugs.
The actress previously told the Herald how she spoke with women who experienced similar struggles in real life and used them as inspiration. She said: "It is hard but at the same time it's fascinating and these women are incredibly inspiring", said Susan who earlier this year lent her support to a campaign run by Ruhama, to raise awareness of prostitution in Ireland.
But although the actress is remaining tight lipped over whether she will be returning for a fourth series --Susan would love to work with Love/Hate writer Stuart Carolan again.
"I love how he writes and finds inspiration from the actors and characters ... that's so amazing to think that someone would work so closely with you."