Is it fair to compare?

As a mother of four children, I find myself sometimes "comparing" them to one another.  Not where they can hear me, but just inside my own little head.  I'm mostly comparing developmental things and milestones.  For example, I will compare how big Tristan is compared to Karissa's size when she was his age.  That's typical mom stuff there.  I think that type of comparison is just fine, and does no harm!  But, when I do other types of comparing, I wonder if I'm over-thinking things, or if I have a valid concern?  Let me explain where I'm going with this.  Two years ago, my son Nathan was in the first grade.  The first grade at his school does the "Flat Stanley" project, where they send a paper version of themselves to a family member or friend in another state and that person becomes the "Flat Stanley" host for several days.  The host family then sends back a "report" of what is special about our state, what we did while we were there, pictures, etc.  In addition, the student would include a letter to the host, written by themselves.  Nathan's letter was VERY legible.  It was written on the type of paper that has the guidelines...you know, a solid line at the top, a dotted line in the middle, and a solid line at the bottom.  It was very short and to the point.  Now, Jacob is in first grade.  He has the same project.  It's the same time of year that Nathan did his project (actually, it's a couple of weeks later than when Nathan had to do his).  Jacob's letter was written on regular wide rule loose leaf paper.  No guidelines.  Jacob's letter was barely legible.  He drew the cutest picture, and I could make out that he drew a picture of our house, and included me, Tommy, Karissa, Nathan, himself, Tristan, Helo and Lilly in the house.  He also drew a picture of his step-sister Brianna in the pool out back.  He even got so detailed as to put the "125" on the mailbox that the mailman was delivering to.  However, the writing part was not so good.  Most of the words were misspelled.  Many were so misspelled that I have been unable to translate them!  Let me give you a sample:

to ma ev thing he like to ent and to do. he like to eat vechtubols a lot and he like to play with bwrub? alus and guns and stuf like that but he will be new so Thristin will not be vavey hapey if you show him it to Thristin for the fisrt time he will pobley not be vavey clos to Thristin.

to Flindue

from Jacob

YIKES!  So, my heart breaks because Jacob is the one that has had the least "Mommy" time of all the kids.  He doesn't have me around to help him with his reading and his homework.  Karissa had my help until the end of 2nd grade.  Nathan had me through the end of Kindergarten (which is when he learned to read).  Jacob didn't have me for ANY school.  Not even Pre-K.  I feel this shows in their development and progress in school.  Jacob still has a speech impediment, and he writes like he talks.  Make sense?

I want to make it CLEAR that I'm pretty sure that Jacob's teacher wasn't privy to the letter he sent me.  I believe that was part of the assignment that may have been optional.  Nathan's letter was most likely seen by his teacher, and I can see some erase marks on his that shows he had it wrong at one point and fixed it.  So, I'm in no way blaming the teachers here.  This is a case of my kids not having anybody around to help them and show them the right way to do things.  Looks like I have my work cut out for me this summer!

If any of you are homeschoolers...any tips on helping Jake to "get it"?  I would appreciate any help I can get!