Miriam Briddon, 21, died in the crash near Ciliau Aeron in March 2014.
Gareth Entwhistle, from the Aeron Valley, admitted causing death by careless driving while under the influence of alcohol.
He was jailed for five-and-a-half-years but his sentence was cut by six months on appeal.
Miss Briddon's family has now launched an online petition for the law to be changed to allow judges to pass harsher sentences on drink-drivers that kill.
Her mother Ceinwen Briddon said: "At the moment nearly 63,000 have signed the petition and I am really pleased with the response.
"We've had a lot of messages from families in similar situations to us, people who have lost someone or whose lives have changed because of drink-driving."
"Usually drink-drivers get three to five years and that is for taking someone's life and they only serve half of that. It's not a deterrent at all.
"Judges need to be able to pass stronger sentences."
Miss Briddon, a fashion designer, had three sisters, including an identical twin.
She was killed instantly when Entwhistle's Volkswagen Golf strayed into the path of her Fiat Punto.
"We know a change in the law is not going to make any difference to Miriam's case but the guidelines need to change for the sake of others," added Mrs Briddon.
"If a stronger deterrent would stop one person getting in the car after drinking and putting another family through what we've been through, it will have been worth it."
A Ministry of Justice spokesperson said: "Our thoughts are with the family and friends of Miriam Briddon.
"We are currently considering the penalties for driving related offences in order to find the best way forward.
"Sentencing is a matter for our independent judges, who make their decisions based on the facts of individual cases."
The family of a Ceredigion woman killed in a collision with a drink-driver is calling for a change in sentencing guidelines.