Staring at the pictures, it looks like a twist of sorts on the traditional granny square. However, my basic internet search yields nothing.

My ideas on what is going on:

Row 1 of the pattern: probably chain 4 (counts as one double crochet and a chain 1, 3 double crochets in chain of previous row, chain 1, 3 dcs, chain 1, until you are at a corner, then you chain two to create the corner and continue with 3 dcs and 1 chain around to the next corner. Eventually, 2 dcs before the turning chain, slip stitch into the 3rd chain of turning chain.

Row 2 (this is my big guess): chain one, single crochet into stitch with slip stitch, chain 3, single crochet in chain one, repeat chain 3 and one single crochet around. End with chain three and slip stitch into first single crochet.

Row 3 (repeat of Row 1): chain 4, 3 dcs in the chain 3 from Row 2, chain 1, repeat around, corners as with Row 1.

Now, on Row 2, I can't confirm that the corners are treated like everything else. I imagine that there are actually four chains at the corner, but I have no proof. So, it's trial and error.

And now I realize how much easier it would be if I could draw it out for you. Describing a pattern in words is just wrong. Converting from visual to verbal to visual again is one step too many.

Oh, and regarding the heart...I have no idea. Are you thinking of adding it later or putting it into the pattern itself? I leave those recommendations to others. Plus, it would be good to get someone else's opinion on the pattern.

It looks likesome kind of modified granny square. But with chains over the rows of DC...
If you could take a higher contrast picture (or maybe against a dark background) it might be easier to see. And of course the other option is to unravel a few of the stitches and watch how they were made, but it doesn't sound like you'd want to do that.

For the marker...you could string a heart bead onto the arn and crochet it in.

Hmm..sorry I wasn't much help, but I've never seen that before.

WOW! You people are absolutely WONDERFUL! Thank you so much for the detailed responses.

Last item first: I think the heart idea was over-ambitious. Maybe I'll make a little chain "ribbon", run it through where I took over, tie a little bow, and tack it down so it won't come untied.

Now back to the pattern: I tried double crochet, but it came out too high, so I started searching my stitch refernce guide and came up with "half-double-crochet." That looks right.

After trying 3 different sized crochet hooks, I found one that matched, but I still have to concentrate on my tension. MIL's work is looser than mine. I think that comes with experience. I know that when I try to teach someone to knit, their work always comes out too tight. (This project has me talking to my yarn, which has DH in stitches of a differant kind.)

I've gone all the way around with the first row, now. The difference between lefthanded and righthanded is very slight--just the angle at the top looks reversed, but I don't think that will show, since the next row will always cover that up.

What I have noticed is that Memaw's pattern blocks are perfectly vertical. Mine slant, making my work look sloppy in comparison. It doesn't really look bad, but it certainly wouldn't win any prizes at the county fair. I was too tired when I quit last night to worry about it, but this morning I'll pay more attention. Maybe I can just straighten each block as I go or maybe I'll just leave it alone. After all, she was the master and I am the student, so having her work perfect and mine flawed might just add to the charm of the whole thing. Our granddaughter will love it either way--she's a sweetheart.

About the chain row at the corners: I noticed on the first row that the chain row almost seems to have a loop at the corners. I'm not there yet, but if I have trouble with it, I may come back here whining and crying. (Fingers crossed I'll be able to come back bragging instead.)

Again my thanks for all your help. I am cautiously optimistic that it will work out okay.

Suz
Easy-Knit-Crochet.com

Oops! I forgot to thank you for the great idea of pulling out a few stitches to analyze the pattern. DUH! I never would have thought of that. I didn't need to do that, here, but I will definitely remember it for next time something like this happens.

Thanks again.

Suz
Easy-Knit-Crochet.com

I've seen that stitch before in a book of crochet stitches, but where? I couldn't find it on the web either, so I looked in a Harmony Guide for it's name so I could Google, but it wasn't in the Harmony Guide.

I saw it as a flat, long row fabric, so the corners are a mystery. I agree with Marikka on the pattern. Good luck, Suz.

Yes, the corners really are a mystery. I've stared at them till I was crosseyed, crochet a couple of rows, ripped them out and tried again. When I used as many stitches as it looked like she used, my corners came out ruffly. I had to reduce the number of stitches to get the corners to lie flat. Also, my work has bigger holes than Memaw's. After 2 complete pattern rows, I can also see that lefthanded crochet is the reverse of righthanded. I would never have noticed a "wrong side" and a "right side" until I scrutinized this project after I took over.

Overall, I think it will be okay. After all--it is what it is.

Thanks for looking for the pattern, but I don't think it came from a book. I think she found it on the back of a yarn label, maybe 15 years ago. She used the same pattern on another one that she finished around 1993 and I don't think that was the first. I'm sure she liked that pattern because it's so quick and easy. I share her love for simplicity.

She started another afghan with squares of raised flowers, attached with fancy lacework. I may never be able to finish that one, but it might be fun to put it on my website and talk about it, here--maybe after Christmas, when things quiet down.

Suz
Easy-Knit-Crochet.com