The sentence is correct if you and the article 'a': "She started her journey a long time ago."
They had a long journey ahead of them. Will you join us on the journey to Spain?
when you started and when you stop
He embarked on a long journey across the mountains. or I journeyed through the desert until I reached an oasis.
On your long journey we pray that no disaster should befall you.
The wholesome meal sustained him for hours on his long journey.
The long interminable journey seemed as if it would never end .
There is nothing wrong with wanting to possess things as long as you don't allow them to possess you.
No matter how long the journey is, one has to take the first step to start off. Until one makes that first step, the journey has not started.
Let's relieve the tedium of this long journey by getting some hot chocolate and chatting.
Your local DMV, can help get you started on what could be a long journey.
The word arduous is an adjective. Her journey was long and arduous, but it ultimately strengthened her character and made her a better person.
The victim's body had lain in the ground so long it had started to decompose.