Although Suzy conducted cash deposits of $10,000 and John conducted a cash deposit of $1,000, because all three accounts are jointly owned by Suzy and John, the three deposits totaling $11,000 were completed on behalf of both Suzy and John, and that requires a CTR.
Here's where the fun starts. You will need four (yes, four) Part I sections.
Part I for Suzy as conductor on her own behalf, with items 2a and 3 checked for the two $5,000 cash deposits to the joint accounts A & B.
Part I for John as person on whose behalf those two cash deposits were made, with 2c and 3 checked.
Part I for John as conductor on his own behalf, with item 2a checked for the $1,000 cash deposit to joint account C
Part I for Suzy as person on whose behalf that deposit was made, with item 2c checked.