If she works as medical assistant through nursing school and is frugal she could MAYBE come out with zero debt and basically you would just figure starting with net worth of 0 and begin calculations with a future wage of $45. Most likely she'd come out with at least $10-15k in student loan debt though (and that's if she goes to community college)
The situation is so vague but I'll give it a quick shot, since i may have an idea of what is reasonable.
I make a little less than $45 an hour and came out of school with $13,000 in debt. I graduated at 23 years old and immediately started working in my field. I bought a house pretty quickly and saved little bit in my first few years. Right now I'm looking at being ABLE to retire at 47, however I will probably stick it out until age 51 because I get a whole bunch of extra perks from my company if I can make it that long (to my earliest official retirement date.)
If she's lucky and starts working full time right away she'll make $90,000 a year. if she stays smart and frugal she can have her student loans paid off in 1 year. (It took me 3 because I bought a house and paid for a wedding in the meantime. she might do the same)
either way, let's put her at 1 year post graduation with no debt and zero net worth earning 90,000 a year.
If she stays frugal and saves 50% of her take home pay, and the market beats inflation by 5% she can retire in 16.6 years
if she only saves 40% using the same conditions she'll retire in 21.6 years
if she only saves 30%, using the same conditions she can retire in 28 years
if she only saves 25% using the same conditions she can retire in 32 years.
all those "years" quoted above are added to whatever age she is when she achieves net worth of zero. so if she is 28 before she has her loans from nursing school paid off and saves 50% then 28 + 16.6 = 44.6 years old
If she saves less than 25% she is basically looking at regular retirement, not early retirement. (assuming it takes her 5-6 years from right now to achieve a net worth of zero).