For Erica Pearce, Aug. 1 started off like any other Saturday morning.  The 30-year-old left her husband and 6-month-old daughter at home and went to her parents' house in Nampa, Idaho. A stay-at-home mom, Erica had been cleaning her folks' home on Saturday mornings for a little extra cash.  But as she made the routine drive over, Erica had no idea that her life, and the lives of another mother and an infant, would forever change.  "I was just driving over to see my mom like usual and I came upon another car that had slowed down and was driving around something in the road," Erica tells PEOPLE.  When her turn to avoid the mysterious roadblock came, she realized that it was a woman and a little girl walking down the yellow centerline of the two-lane road. As she slowly passed, Erica noticed the woman was barefoot and carrying a second child who was wearing nothing but a diaper.  "The first thing that really caught my attention is that the baby was only in a diaper and it was pretty chilly that early in the morning. It was all just odd. Not the type of thing you see on a daily basis, at least not around here," Erica says.  While she slowly passed them and tried to make sense out of what she was seeing in her rearview mirror, Erica suddenly felt a calling, a sensation she had never felt before.  "Once I passed her, my spirit immediately told me to turn around, something's wrong here," Erica says. So she drove back and pulled up beside them to ask the woman if she needed any help.  "She didn't even look at me or respond at all. I got this really bad feeling that something wasn't right," Erica says.  She called 911. While on the phone with dispatch, Erica turned the car around again to follow them. She pulled over by a stop sign and watched as the three walked off the main road and down a dirt trail. Then, suddenly, the woman and baby vanished.  "She kept walking along and then all of a sudden she just fell and disappeared," Erica says. She ran over to where they disappeared and found the little girl sitting on a bank above a small irrigation canal sobbing. The woman was submerged in the canal, and the baby, up to his neck in the water, was crying.  "My instinct was to get the baby," Erica says. She jumped in the chilly water while still on the phone with the police. The water was slightly less than a foot deep but very muddy. Erica was able to grab the baby and lift the incoherent woman's head up above the water. But she wasn't sure what to do next. Luckily, less than a minute later another couple showed up to help.  "It was a godsend," she says of the couple, who took the baby and cell phone from her.  Erica then tried to lift the woman, later identified as 22-year-old Regina Dilworth, out of the water, but Dilworth fought her. "As I was trying to move her, she started to scream. She just kept screaming, 'I'm sorry, God. I'm sorry, God' over and over," Erica says.  Soon thereafter the police showed up. The children were taken into protective custody, and Dilworth  a variety of charges, including felony injury to a child.  Reportedly high on a combination of bath salts and an opiate that she injected the night before, Dilworth had believed her children were possessed and needed to be baptized.  A model student through high school, Dilworth apparently fell in with a bad crowd and developed drug problems in her early adulthood that led to numerous legal problems. But Erica believes there is still reason to have hope.  "I'm a Christian and really believe God brought me to that place and the Holy Spirit guided me," Erica says. "In the moment you don't really think about it. But in the aftermath, when you have time to see the little things, the little moments that led to that big moment, you look back on it and you say, 'Wow. Thank you, God!' "  As for all the press the incident has gotten, Erica has a simple outlook. "There's been a lot of talk about God with all this and how could God let this woman do that to herself and her children," Erica says, "but I choose to believe that God was there that day and is using this situation to help reach out to other people."
Erica Pearce tells PEOPLE about rescuing the infant from his ailing mother, who was reportedly high on bath salts