Welcome back Kerrin!
I searched the subscription site Roots Ireland and possibly have a lead. I did not find a marriage record for Thomas and Johanna but located five baptismal records for Elizabeth 1835 Michael 1837 Thomas 1839 Martin 1843 Mary 1847 The parents were Thomas Gibbons and Judith or Joanne Campion which is fairly close to your Johanna. The children's names do not exactly macth up with your list but some of the children could have died young in Ireland.around the time of the An Gorta More. I copied below the oldest and youngest child records and you can see that in 1847 they lived in Griague and the RC parish was Graigue Killeshin. I believe the are is in northwest Carlow very close to the Laois border.
Name:Elizabeth GibbonsDate of Birth:
Date of Baptism:14-Nov-1835Address:Dublin Rd.Parish/District:CATHEDRAL OF THE ASSUMPTIGender:
Father:Thomas GibbonsMother:Judith CampionOccupation:
Sponsor 1 /
Informant 1:Patrick Moore Sponsor 2 /
Informant 2:Mary Lawlor
Name:Mary GibbonsDate of Birth:
Date of Baptism:18-Jul-1847Address:GraigueParish/District:GRAIGUECULLEN/KILLESHINGender:
Father:Thomas GibbonsMother:Joanne CampionOccupation:
Sponsor 1 /
Informant 1:Richard Smyth Sponsor 2 /
Informant 2:Mary Dean