Blanket repair for mom

So this is a blanket a family member made for my mom.  The first time she washed it we found out it was sewn together using plastic thread.  Which melted, broke and made a mess of the blanket.

My much much much much older sister tried to pull out all the melted plastic, in the process disasembling what was still left connected with it.   So I have no idea how it was supost to look originaly.  I am just going to wing it, since the boarder is still attached and a round of squares  are still attached to the boarder I am going to be sewing this from th outside in.

I plan on working it in a corner to corner style, I started by closing up the edges around the blue square connecting it to the edge of the green and orange that where still attached to the boarder on either side.   Then I start on the other side of the green, connecting it to the blue, I picked a pink square out of the pile of loose squares work its edge acrosss both green and orange then sewed up the side of the two orange squares. 

I am hopping by doing it this way there will be less matching sides up issues.  It seems like not all of the squares are exactly the same some have more/less stitches than others.

I am just doing a simple whip stitch with that ball of rainbow yarn, starting on the back side and securing with a knot at every corner I get to for extra paranoia.

I may try slst'ing the next row together on the back side to see if that works up fast and feels sturdyer.