But best would be to have full control over those lines so create text lines with spans and give them classes so you can style them with CSS in one place. Makes life way easier.
[{"id":"510773b5.7aed1c","type":"ui_text","z":"c0ddb509.b04f48","group":"93fae10c.09faa","order":6,"width":0,"height":0,"name":"","label":"Label is here","format":"<span class=\"firstline\">text first line</span><br><span class=\"secondline\">text second line</span>","layout":"row-spread","x":480,"y":1540,"wires":[]},{"id":"4dd32966.9d2668","type":"ui_template","z":"c0ddb509.b04f48","group":"93fae10c.09faa","name":"CSS","order":7,"width":0,"height":0,"format":"<style id=\"dashboard-custom-styles\">\n .nr-dashboard-widget-Label_is_here .value {\n font-weight: normal; \n line-height: 12px;\n text-align: right;\n }\n .nr-dashboard-widget-Label_is_here .value .firstline{\n font-size:18px;\n font-weight:bold;\n }\n .nr-dashboard-widget-Label_is_here .value .secondline{\n font-size:10px;\n }\n</style>","storeOutMessages":true,"fwdInMessages":true,"resendOnRefresh":true,"templateScope":"global","x":460,"y":1500,"wires":[[]]},{"id":"2dcd586e.58f578","type":"ui_text","z":"c0ddb509.b04f48","group":"93fae10c.09faa","order":6,"width":0,"height":0,"name":"","label":"Another text widget","format":"<span>text first line</span><br><span>text second line</span>","layout":"row-spread","x":490,"y":1580,"wires":[]},{"id":"93fae10c.09faa","type":"ui_group","name":"Default","tab":"6ff5405c.a8e6","order":1,"disp":true,"width":"6","collapse":false},{"id":"6ff5405c.a8e6","type":"ui_tab","name":"TEST","icon":"dashboard","order":3,"disabled":false,"hidden":false}]
