Praise be to Allah.
The case of a woman getting married again is something that God has predestinated and is a success granted by Him. This matter could be fulfilled by: (Doaa) praying to Allah to provide her with another husband. By the guide of charitable people for a suitable man. By one of her female friends who knows her status and mentions her to one of her relatives, also this could be the fruit of philanthropic project for achieving marriage relations considering the state of the man and the woman and what is suitable for every one and is controlled by trustworthy faithful people.
And as for the guardian, it is a must no matter the woman has been married before or not. The prophet (peace be upon him) said: Any woman who gets married without the permission of her guardian, her marriage is false, her marriage is false, her marriage is false.[Narrated by Al Termithy # 1102, Abou Dawood, Ibn Maga & El Albani said that it is authentic in his book Sahih Al Gamia # 2709 ].
It is preferable for the person proposing (for the first time) to look at the woman he is proposing to because the prophet (peace be upon him) said:
Go and look at her [Narrated by Muslim # 1424].
And for what Al Nasaee narrated: Al Mugira Ibn Shoba said: Someone proposed to a woman at the time of the prophet (peace be upon him) so the prophet asked him: (Did you look at her?) He said no. He said: (look at her, by doing this it will be more likely to have a harmonious marriage with everlasting love.[Narrated by Al Nasaee & others, El Albani said that it is authentic in Sahih Al Gamia # 859].
Most of the scholars agreed that the man proposing for marriage is allowed to look at the womans face as it is the place that gathers all the charms, and her hands (their face and back), i.e. she should appear in the same state as in her prayers.
This should be without staying alone with each other in a privet place. And without touching one another. He may look, in their meeting, at her more then one time as long as he needs this, until he decides if hes going to marry her or not.