There is absolutely nothing wrong or undesirable for a Muslim in getting married within one year of a family member's death.

Mourning period for the dead in Islam is for three days only --except in the case of a woman mourning for her husband; for she should mourn him four months and ten days. Widows are allowed to get married, if they wish, after the expiry of the idda (the prescribed period of mourning) --as is clear from the Qur'an as well as the precedents of the Prophet, peace be upon him, and his companions.

Based on these strong precedents, no scholar or jurist, considers it objectionable or even undesirable to get married after the prescribed period of mourning.

The Prophet, peace be upon him, saw angel Jibreel in his original form only twice, as we can learn from the well attested traditions. The first vision occurred in Ajyad in Makkah, following his first experience with the revelation. The second incident occurred during his mi'raj ( ascension ) into the celestial spheres; it has been referred to in the Qur'an as 'one of the mighty signs of his Lord'. None of these angelic manifestations, as far as we learn from the sources, were seen by anyone else --including Aishah, Allah be pleased with her.

Jibreel, however, used to appear to the Prophet in a human form as happened on a number of occasions; when he did so, he could be seen by others; but since he appeared no different from anyone else, the companions did not recognize him. Thus we read in the famous hadith jibreel: Once a man, well groomed, and, impeccably attired, walked into the majlis (assembly) of the Prophet, peace be upon him. He came and sat in front of the Prophet, and asked him a number of questions on islam, iman and ihsan, etc., but, to the Companions' utter surprise, upon hearing the Prophet's answers, he commented upon them, saying,' you are right! ' This made the companions suspicious; when he went away, the Prophet asked one of his companions to look for him; but the companion reported back that he was no where to be seen; whence the Prophet told them,' that was Jibreel, who came to teach you religion! '

On a number of occasions, Jibreel would assume the form of Dihya al-Kalbi --one of the Prophet's companions, who was a handsome man.

We read in a well attested report from Aishah: Once on seeing the Prophet conversing with Dihyla al-Kalbi for a long while, Aishah asked him,' I saw you conversing so long with Dihya al-Kalbi! ' , then the Prophet corrected her,' no, it was Jibreel, and he conveys his salaam to you'.

We find no mention in the sources of any of the Prophet's other wives ever seeing angel Jibreel. However, we read, again, in Aishah's narrative of the early years of revelation to the Prophet, peace be upon him: Once the Prophet conveyed to Khadijah the greeting of Jibreel, on his behalf, as well as the glad tidings of a mansion in jannah  (paradise) awaiting her after death.

The prescribed period of mourning for the dead in Islam is three days, as reported in a number of well attested traditions from the Prophet, peace be upon him. The only exception is the mourning of a wife over her husband, which is for four months and ten days.

So the re is no precedent in the sunnah of the Prophet for the practice you mention; nor was it practiced by the pious generations after him. Hence, it is an innovation which has crept into the Muslim community.

We are, however, to keep alive the memory of the dead through virtuous acts. Offering du'as for them, visiting their graves and praying for them, fostering their ties of kinship, giving charities, reading Qur'an on a voluntary basis, etc. are all considered good ----as long as we do not fix a date of seven or fourteen or forty, etc. We have sufficiency in these practices; hence we do not need to resort to innovations.