Manjinder Sandhu was in the adjoining residential flat of the Sai Food Market in Prince Albert Rd, St Kilda, when she heard someone enter the dairy about 7.15pm.
However, when Ms Sandhu entered the shop she found a woman wearing a balaclava on the other side of the counter.
''I could see her eyes and nose and when I approached her she pointed a knife at me and said `Where is the cash?','' Ms Sandhu said.
''As soon as I saw her pointing the knife to me I ran straight back to the house.''
She bought the store only three weeks earlier and the ordeal had left her shaken and questioning the intentions of everyone who entered the dairy.
``I was so scared my legs were shaking and even today when someone comes in to buy anything I wonder if I can trust them,'' she said, tears welling in her eyes.
``Now I fear whether I can trust any person.
``At the moment I just want to forget this.''
The previous owner ran the dairy for a year and was never robbed, she said.
However, the store was targeted twice in 2012 and in 2013.
Police told Ms Sandhu the description of the offender was similar to the young woman who robbed nearby restaurant Tandoree Garden at knife-point on Wednesday.
Ms Sandhu had struggled to remember specific details of the woman's appearance.
``I just remember the head covering and she had dark clothing on,'' she said.
``She was looking like quite an attractive girl ... near 20s or in her early 20s.
``She said `Give me the cash', that's all she said.''
Police had told her they were following leads in relation to the offender.
Victim Support had also be in contact with her.
``At the moment I think I'm fine, it will just take me a little time to trust people again.''
Senior Sergeant Ben Butterfield said inquiries were ongoing in relation to the robbery.
