Skip that last idea. I think It was the wrong couple, wrong area, similar names.
But here is a Brithe, b. 1857 in Manger, like the woman on the 1900 census, who is baptised and living at a Dahle farm.http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbas...
6817 6817 67 1803 Berthe Marie k 0904 H.D. conf. Grdbrg. Knud Olsen Ingeborg Hansdtr Dahle af Nils Monsen Dahle 1857 Ægte Herløe
I would like to find her marriage, or at least more details about her life.
Here is Berthe M. Knudsdatter Dahle b. 1857 on the 1865 census.
I'm still digging to see if this Berthe is related to your first (trying to find if she is married to a Halvor Sæbo eventually)
In order to find if she is related, maybe the Manger Bygdebok would have a family history of the farm in it, and on that farm and family history for Manger, the artist JCDahl might be listed.
Here is the 1865 census:http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbas...
District no. Page School distr. Local parish Parish Farm Remarks (farm) Title
733 10 451 33de, 32de, 31te, 30te Herlø Manger Dahle* 679a 1
Pers.no. Household Given name Last name Family pos. Occupation Marital status Age Sex Birth place Cattle Sheep Oat Potatoes
4389 12 1 Knudt Ols. Husfader Gaardbr Bygselmand g 47 m Manger 3 7 1 1/2 3
4390 13 Ingeborg Hansd. hans Kone g 55 k Manger
4391 14 Olina Knudsd. deres Datter ug 18 k Manger
4392 15 Berthe M. Knudsd. deres Datter ug 9 k Manger
4393 16 Mons Johns. Tjennestekarl ug 18 m Manger
This could be the death of your Halvor Sæbo
Døde i Årstad (Bergen) 1915-1980 http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbas...
5494 0 1311 1943 Solheim gamlehj. Begravet Solheim. Avdød Enkemann, fhv. Verksarb. Halvor Sæbø Vikensgt. 6 m Manger 1854 1501 0711
died Nov. 7, 1943, buried Nov. 13.
Solheim oldpeople's home, buried in Solheim, widower, Halvor Sæbø. address? Vikensgt. #6. born in Manger, 1854, Jan 15.