Marion, the reason you are unable to find what you are looking for is because you are ignoring the first rule of genealogical research which is to get all the information possible from the most recent generation, and then move back one generation at a time, and finding out everything you can for that recent generation before investigating their parents' generation.
This was why I suggested you buy the two death certs you were certain were your relatives to see what information was given there, before looking for anyone else.

When you have Amy Elizabeth's death cert details these should help lead you to her accurate marriage and birth certs which you should also buy, in order to confirm you have her correct parents. Only then should you start researching her parents' generation and getting their details from certs, censuses, wills, etc., to confirm each step before going on to an earlier generation. Frances has supplied you with a lot of leads for these from online and personal records, but you need to be certain each person is correct by taking it slowly, buying civil registration certs (which are official records and therefore likely to be accurate - especially the births and marriages), and not trying to start off in the middle with Ancestry.
Working this way saves you going down wrong tracks and becoming confused.

The 1911 census which Frances suggested has this for Peter Mylchreest, which MIGHT fit the information you have from your father (Household transcript from Findmypast):

Person: MYLCHREEST, Peter
Vessel: Duckess
Port/place: A E Dock Preston Lancs

Name/ Relation/ Condition /Yrs married/ Se x/ Age/ Birth Year/ Occupation/ Where born:
MYLCHREEST, Peter, Crew, Married, M, 37, 1874, Mate, Isle of Man Port St Mary.
RG number: RG14, Piece: 25325
Reference: RG14PN25325 RG78PN1448 RD476 SD4 ED23 SN8
Registration District: Preston
Sub District: West Preston
Enumeration District: 23
Parish: Preston
Address: A E Dock Preston Lancs; County: Lancashire.

Sue